Existing pipe cut-off method, existing pipe slitting method, piping structure, and valve insertion method for inserting a valve in a line without stopping passage of water or fluid

ABSTRACT

The invention relates to an existing pipe cut-off method and slitting method, by which an existing pipe made of cast iron and steel can be cut off. With a cut-off method according to the invention, first, a part of an existing pipe  1  is enclosed and sealed up by a seal-up housing  2  in an airtight state, a cutting tool  30  having a plurality of blades  30   c  is accommodated in the corresponding seal-up housing in a state the cutting tool is attached to the abovementioned seal-up housing  2.  Next, the cutting tool  30  is fed toward the center of the abovementioned existing pipe  1  while slitting the existing pipe  1  by rotating the cutting tool  30  by power of a prime mover, and the abovementioned existing pipe  1  is cut off by the cutting tool  30  by turning the abovementioned seal-up housing  2  in the circumferential direction R of the existing pipe  1.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an existing pipe cutoff method,and a valve insertion method for inserting a valve in a line withoutstopping passage of water or fluid, etc.

[0003] 2. Description of Prior Arts

[0004] Conventionally, a valve insertion method for inserting a valve ina line without stopping passage of water, by which an existing pipe iscut off without stopping passage of water and a valve is inserted intothe cut-off portion of the existing pipe in a line including theexisting pipe, has been already publicly known.

[0005]FIG. 72 shows a sketch of a conventional method disclosed inJapanese Laid-Open Patent Publication Nos. 44167 of 1980, 83690 of 1981,120886 of 1981, and 47089 of 1982.

[0006] The method illustrated in the drawing is such that cuttingequipment 500 is fixed at an existing pipe 1, the cutting equipment 500and existing pipe 1 are enclosed and sealed up by a seal-up housing 501,and the left and right blades 502 are rotated along the cuttingequipment 500 in order to cut off the existing pipe 1. Thereafter, avalve is inserted into a line 1A instead of a cut-off section 10 of theexisting pipe 1 by opening and closing an operation sluice valve 503. Inthe prior art, since the cutting equipment 500 is accommodated in theseal-up housing 501, the seal-up housing 501 is made large-scaled toresultantly expand the digging area, etc.

[0007]FIG. 73 shows a sketch of a prior method disclosed in U.S. Pat.No. 5,611,365 and International Laid-Open WO 97/31207.

[0008] With the method illustrated in the drawing, an existing pipe 1 isenclosed and sealed up by a seal-up housing 600, a cutting tool 602 isfixed at and attached to the tip end of a gate valve 601 installed atthe seal-up housing 600, and the gate valve 601 is turned together withthe seal-up housing 600, wherein an existing pipe 1 is cut off by thecutting tool 602. According to the prior arts, since the cutting tool602 is turned by rotations of the seal-up housing 600, it is notnecessary that the seal-up mechanism for turning the cutting tool 602 isprovided in a seal-up housing 600. Therefore, the seal-up housing 600can be small-sized.

[0009] However, with such conventional cut-off methods, a chip-likecutter 602 bites an existing pipe 1. Therefore, in a housing of cuttinginto an existing pipe 1 made of cast iron or steel, the seal-up housing600 must be turned many times, wherein it takes much time to cut off.Furthermore, there is a fear that rubber packing to seal between theseal-up housing 600 and existing pipe 1 is damaged.

[0010]FIG. 74 shows a sketch of a conventional cut-off method disclosedin U.S. Pat. Nos. 3,650,547, 3,703,906, and 3,735,775.

[0011] With the prior art shown in the drawing, an existing pipe 1 isenclosed and sealed up by a seal-up housing 700, and after a cuttingwheel 701 attached to the seal-up housing 700 is caused to bite theexisting pipe 1 by a lead screw 702, the cutting wheel 701 is turnedtogether with the seal-up housing 700, whereby the existing tube 1 iscut off.

[0012] With the cutting method, since the cutting wheel 701 has a smoothouter circumferential part, it is impossible to cut off an existing pipe1 made of cast iron and steel.

[0013]FIG. 75(a) and FIG. 75(b) show views of a conventional method forinserting a valve in a line without stopping passage of water, which isdisclosed in U.S. Pat. No. 3,948,282.

[0014] With the conventional method shown in these drawings, an existingpipe 1 shown in FIG. 75(a) is enclosed and sealed up by a seal-uphousing 800. Subsequently, an operation sluice valve 801 is attached tothe seal-up housing 800. Thereafter, a circular hole 803 is drilled byusing a hole saw 802 in compliance with an already known method. Afterthe drilling is completed, as shown in FIG. 75(b), a valve body 804which is fitted into the drilled circular hole 803 is inserted therein.

[0015] With the conventional valve inserting method, since the hole 803which has roughly the same diameter as the inner diameter of theexisting pipe 1 is provided, the seal-up housing 800 shown in FIG. 75(a)is made longer in the axial direction S and is made large-sized.

[0016] Furthermore, with the conventional inserting method, sincehydraulic pressure is given to the valve body 804 shown in FIG. 75(b)with respect to a large area equivalent to the circular hole, thediameter of the valve rod 806 is unavoidably made large.

[0017] Still furthermore, with the conventional inserting method, thecircumferential edge 805 of the hole 803 at the existing pipe 1 is madethin, and pressure resulting from the valve body 804 is applied to thecircumferential edge 805, wherein the existing pipe 1 is liable to bebroken.

[0018]FIG. 76(a) and FIG. 76(b) show the outline of a conventional valveinsertion method for inserting a valve in a line without stoppingpassage of water, which was disclosed in U.S. Pat. No. 4,156,598.

[0019] In the prior art shown in these drawings, the existing pipe 1 inFIG. 76(a) is enclosed and sealed up by an seal-up housing 800. At thistime, a hole saw 802 and a valve body 804 are accommodated in advance inthe seal-up housing 800. Thereafter, a circular hole is drilled at theexisting pipe 1 by the hole saw 802. After the drilling is completed,the seal-up housing 800 is turned as shown by the arrow 850 in FIG.76(a). After that, a valve body 804 is inserted into the circular hole803 in FIG. 76(b).

[0020]FIG. 77 shows the outline of a conventional valve insertion methodfor inserting a valve in a line without stopping passage of water, whichwas disclosed in U.S. Pat. No. 1,989,768.

[0021] In the prior art shown in this drawing, the existing pipe 1 inFIG. 77 is enclosed and sealed up by a seal-up housing 501. At thistime, cutting equipment 500 and a sluice valve 510 are accommodated inadvance in the seal-up housing 501. After the cutting equipment 500having a blade 502 cuts off and removes the existing pipe 1, the sluicevalve is inserted instead of the cutting equipment 500.

[0022] The prior arts shown in FIG. 76(a), 76(b), and FIG. 77 are ableto quickly insert a valve after the cutting is completed. But with theprior arts shown in FIG. 76(a), 76(b), and FIG. 77, since it isnecessary to accommodate a hole saw 802 or cutting equipment 500, thesize of which is equivalent to that of the valves 804 and 510 to beinserted, in the seal-up housing 800 or 501, the seal-up housings 800and 501 are obliged to be large-scaled.

SUMMARY OF THE INVENTION

[0023] The present invention has been developed to solve the problemsinherent to the prior arts, and it is therefore a major object of theinvention to provide an existing pipe cut-off method by which theexisting pipe made of cast iron or steel can be cut off without causingits seal-up housing to turn many times.

[0024] It is another object of the invention to provide a method forinserting a valve in a line without stopping passage of water, in whichthe abovementioned method is employed.

[0025] It is still another object of the invention to provide a pipingstructure in which an existing pipe is scarcely damaged, an existingpipe slitting method by which the existing pipe can be slit to such ashape as the existing pipe is scarcely damaged, and a method forinserting a valve in a line without stopping passage of fluid.

[0026] In order to achieve the abovementioned main object, in a cut-offmethod according to the invention, a cutting tool, which is fixed at arotatably supported cutter shaft and is provided with a plurality ofblades, is accommodated in a seal-up housing in a state where thecutting tool is attached to the abovementioned seal-up housing whileenclosing, in an airtight state, a part of an existing pipe by theabovementioned seal-up housing which is divided into plural sections inthe circumferential direction of the existing pipe.

[0027] Subsequently, the abovementioned cutting tool is fed roughly inthe cross direction of the abovementioned existing pipe in a state ofperforming a slitting motion to slit the abovementioned existing pipe byrotations of the abovementioned cutting tool by causing theabove-mentioned cutting tool to rotate on the abovementioned cuttershaft by power of a prime mover, wherein the abovementioned cutting toolis caused to perform a feed motion with the above-mentioned cutting toolturned in the abovementioned circumferential direction by causing atleast a part of the above-mentioned seal-up housing to turn in theabovementioned circumferential direction of the abovementioned existingpipe, and the abovementioned existing pipe is cut off by theabove-mentioned cutting tool.

[0028] According to the invention, since the existing pipe is slit byrotating the cutting tool on its cutter shaft, any existing pipe made ofcast iron or steel is able to be easily cut off by turning the seal-uphousing one to three times. Therefore, the cut-off time can beshortened, and there is no fear that rubber packing secured at therotating and sliding portion is damaged.

[0029] In the invention, “existing pipe” means a pipe through whichfluid such as water flows and is generally buried under the ground.

[0030] “Seal-up” does not mean “completely sealed” but means such astate where work can be carried out without stopping passage of water orfluid. Therefore, “seal-up housing” means a housing which has such apressure resisting capacity, by which it can withstand the pressure offluid flowing through the existing pipe, and has a sealing capacity tosome degree.

[0031] Furthermore, “enclosed and sealed up in an airtight state” meanssuch a sealed up state where work such as inserting a valve in a lineafter cut-off or slitting is not hindered, for example, wherein a waterdischarge port is provided at the seal-up housing and is made openduring slitting of an existing pipe, and cutting chips may be dischargedthrough the discharge port together with water.

[0032] Since a “cutting tool” used in the present cut-off method has aplurality of blades, the corresponding cutting tool does not include acutting chip and a cutter wheel having a single continuous blade. As the“cutting tool” used in the cut-off method, a columnar cutting toolhaving a plurality of blades on its tip end and its outercircumferential surface may be used in addition to a diamond wheel and ametal slitting saw, etc.

[0033] Here in the specification, “pillar shape” means a conicaltrapezoidal shape in addition to a columnar shape, and includes such ashape, in which a conical shape is added to a column, and a conicalshape. Furthermore, it may be of a short-pillar shape in comparison withthe outer diameter of a cutting tool.

[0034] Furthermore, in a housing of slitting an existing pipe havingmortar lining on its inner circumferential surface, it is preferablethat a cutting tool having a plurality of blades made of an ultra-hardalloy, or a cutting tool, the blades of which are made of diamondgrains, is used.

[0035] Furthermore, in the invention, “slitting” means slitting a partof a pipe wall by rotating a plurality of blades. On the other hand,“cut-off” means cutting off a pipe into two or more sections.Furthermore, “slitting motion” means causing a plurality of blades torotate on the cutter shaft. On the other hand, “feeding motion” meanscausing the abovementioned cutting tool to move to the position where anew part of the pipe wall can be progressively cut off or slit by thecutting tool.

[0036] In the invention, “feeding the cutting tool roughly in the crossdirection of the existing pipe and causing the seal-up housing to turnin the circumferential direction of the existing pipe” means bothhousings, one of which is turning the seal-up housing after the cuttingtool is fed roughly in the cross or diametrical direction of an existingpipe, and the other of which is turning the seal-up housing whilefeeding the cutting tool roughly in the cross or diametrical directionof an existing pipe.

[0037] It is possible to insert a valve into the cut-off position of theexisting pipe in a line after the existing pipe is cut off by thecut-off method of the invention.

[0038] Furthermore, in the invention, “inserting a valve (in a line)”does not mean physically inserting a valve or valve body in a cut-opensection of an existing pipe but means installing a valve, which can stopwater or regulate the flow quantity in an existing line, in thecorresponding line.

[0039] Herein, “valve” means the entire valve, that is, valve assembly,including a valve body, valve housing, valve rod, etc.

[0040] Furthermore, “valve body” means a member which clogs a flowpassage, in the case of a sluice valve, it is generally called a gate,and in the case of a butterfly valve, it is a member which turns aroundthe valve rod,

[0041] Still furthermore, “valve housing” means a member whichaccommodates the valve body, regardless of its opened or closed state ofthe valve body.

[0042] In order to achieve the abovementioned other object of theinvention, a piping structure according to the invention is providedwith an existing pipe, a seal-up housing, a sluice valve body and avalve rod.

[0043] The abovementioned existing pipe has a slit groove obtained bynotching the corresponding existing pipe in a range of approximately 180degrees in the circumferential direction thereof.

[0044] The abovementioned seal-up housing is divided into pluralsections in the circumferential direction of the abovementioned existingpipe and encloses and seals up the existing pipe in an airtight state.

[0045] The sluice valve body has rubber packing which is brought intocontact with the inner circumferential surface of the existing pipe anda cut-off surface forming the abovementioned slit groove in thecorresponding existing pipe in the open state (closed state). The sluicevalve body moves in the diametrical direction of the above-mentionedexisting pipe in the seal-up housing and invades the existing pipethrough the slit groove, wherein the abovementioned rubber packing stopsa stream of fluid in the existing pipe.

[0046] The abovementioned valve rod causes the valve body to moveroughly in the cross direction.

[0047] In a preferred embodiment of the invention, the slit groove isformed by slitting an existing pipe by the cutting tool.

[0048] Furthermore, in another preferred embodiment of the invention,the slit surface forming the abovementioned slit groove is formed sothat the angle with respect to the surface of the existing pipe at thecorresponding part is set in a range from 45 degrees through 90 degrees.

[0049] Furthermore, in still another preferred embodiment of theinvention, both end portions of the abovementioned slit groove in thecircumferential direction are made roughly U-shaped.

[0050] A piping structure according to the invention is completed byinserting a valve in a line, by a method for inserting a valve in a linewithout stopping passage of fluid according to the invention, afterslitting an existing pipe by, for example, an existing pipe slittingmethod of the invention. Furthermore, “without stopping passage of fluid(water)” means that work is carried out without stopping a stream offluid (for example, water) flowing in a line.

[0051] That is, in an existing pipe slitting method according to theinvention, a cutting tool, which is rotatably supported on the axialline established roughly in the cross direction of an existing pipe andis provided with a plurality of blades on the tip end face and outercircumferential surface of the columnar portion thereof, is accommodatedin a seal-up housing in a state where the cutting tool is attached tothe abovementioned seal-up housing while enclosing, in an airtightstate, a part of the abovementioned existing pipe by the above-mentionedseal-up housing which is divided into plural sections in thecircumferential direction of the existing pipe. Subsequently, theabovementioned cutting tool is fed roughly in the cross direction of theabove-mentioned existing pipe in a state of performing a slitting motionto slit the abovementioned existing pipe by rotations of theabovementioned cutting tool by causing the abovementioned cutting toolto rotate on the above-mentioned axial line by power of a prime mover,wherein the above-mentioned existing pipe is slit by the abovementionedcutting tool in a range of approximately 180 degrees in thecircumferential direction thereof by causing the abovementioned cuttingtool to perform a feed motion with the abovementioned cutting toolturned in the abovementioned circumferential direction by causing atleast a part of the abovementioned seal-up housing to turn in theabovementioned circumferential direction of the abovementioned existingpipe.

[0052] After the existing pipe is slit in a range of approximately 180degrees by the abovementioned cutting tool in conjunction with aslitting method according to the invention, a valve is inserted in aline. The valve body of the valve invades the existing pipe through theslit groove, clogs the slit groove itself, and is pressure-fitted to theinner circumference of the existing pipe, thereby closing theabovementioned existing pipe.

[0053] According to the invention, a cutting tool, the axial line ofwhich is set in the diametrical direction of an existing pipe, is fed inthe circumferential direction of the existing pipe to slit the existingpipe like a deep groove. Therefore, since the peripheral edge portion ofthe slit groove at the existing pipe is not made thin, there is no fearthat the existing pipe is damaged when a valve body is fitted in theabovementioned slit groove.

[0054] Furthermore, in the slitting method, “slitting in a range ofapproximately 180 degrees in the circumferential direction” meansslitting through an existing pipe to such a degree that the valve bodyhaving a size approximate to the inner diameter of the existing pipe canbe inserted thereinto through the slit groove.

BRIEF DESCRIPTION OF THE DRAWINGS

[0055]FIG. 1a is a cross-sectional view of a seal-up housing showing thefirst preferred embodiment of an existing pipe cut-off method accordingto the invention, and

[0056]FIG. 1(b) is a longitudinally sectional view of a cutting toolused for the method,

[0057]FIG. 2 is a longitudinally sectional view showing the entirety ofa seal-up housing, cutting equipment, etc.,

[0058]FIG. 3 is a longitudinally sectional view mainly showing thecutting equipment before cutting is started,

[0059]FIG. 4 is a longitudinally sectional view mainly showing thecutting equipment after cutting is finished.

[0060] FIGS. 5 are sectional views, (a) of which is a longitudinallysectional view of a bar-like valve, (b) of which is a cross-sectionalview of the bar-like valve in its open state, and (c) of which is across-sectional view taken along the line Vc-Vc in FIG. 5(a),

[0061]FIG. 6 is a sectional view showing the entirety of an existingpipe after the cutting is completed,

[0062]FIG. 7 is a longitudinally sectional view showing a state whereinan operation chamber is assembled,

[0063]FIG. 8 is a sectional view showing the structure of a press rod,etc.,

[0064]FIG. 9 is a sectional view of the entirety, showing a state wherea seal-up housing is moved onto a cut-off section by using the pressrod,

[0065]FIG. 10 is a sectional view showing a state where the cut-offsection is removed,

[0066]FIG. 11 is a sectional view showing a state where a valve ishoused in an operation upper chamber,

[0067]FIG. 12 is a part sectional view showing a process of temporarilystopping water,

[0068]FIG. 13 is a longitudinally sectional view showing the entirety ofthe process,

[0069]FIG. 14 is a sectional view showing a completed state,

[0070]FIG. 15 shows a modified version of the first preferredembodiment, (a) of which is a sectional view showing major parts of themodified version, (b) of which is a cross-sectional view of a plate-likevalve body, and (c) of which is a front elevational view showing a metalslitting saw,

[0071]FIG. 16 shows cutting equipment of another modified version, (a)of which is a sectional view taken along the line XVIa-XVIa in FIG.16(b), and (b) of which is a sectional view taken along the lineXVIb-XVIb in FIG. 16(a),

[0072]FIG. 17 is a cross-sectional view of a seal-up housing showing asecond preferred embodiment of an existing pipe cut-off method accordingto the invention,

[0073]FIG. 18 is a longitudinally sectional view showing the entirety ofa seal-up housing and cutting equipment, etc.

[0074]FIG. 19 is a longitudinally sectional view mainly showing thecutting equipment before the cutting is started,

[0075]FIG. 20 is a longitudinally sectional view showing the above afterthe cutting is finished,

[0076]FIG. 21 is a longitudinally sectional view showing a state wherean operation upper chamber is assembled after the cutting is completed,

[0077]FIG. 22 is a sectional view showing a state where a cutoff sectionis removed.

[0078]FIG. 23 is a sectional view showing a state where a valve ishoused in the operation upper chamber,

[0079]FIG. 24 is a sectional view showing a state where a valve isinserted,

[0080]FIG. 25 is a sectional view showing a state where the valve iscompletely inserted,

[0081]FIG. 26 is a cross-sectional view of major parts showing amodified version of the second preferred embodiment,

[0082]FIG. 27 is a sectional view taken along the line XXVII-XXVII inFIG. 26,

[0083]FIG. 28 is a cross-sectional view of the same modified versionafter the cutting is finished,

[0084]FIG. 29 is a cross-sectional view of a seal-up housing showing thethird preferred embodiment of an existing pipe cut-off method accordingto the invention,

[0085]FIG. 30 is a longitudinally sectional view showing the entirety ofa seal-up housing, cutting equipment, etc.

[0086]FIG. 31(a) is a longitudinally sectional view mainly showing thecutting equipment before the cutting is started, and

[0087]FIG. 31(b) is a perspective view of an end mill.

[0088]FIG. 32 is longitudinally sectional view showing the cuttingequipment after the cutting is started,

[0089]FIG. 33 is longitudinally sectional view showing a state where anoperation upper chamber is assembled after the cutting is completed,

[0090]FIG. 34 is a sectional view showing a state where the cuttingequipment is removed,

[0091]FIG. 35 is a sectional view showing a state where the valve body,valve cover, etc. of a sluice valve are housed in an operation upperchamber,

[0092]FIG. 36 is a sectional view showing a state where the valve isinserted,

[0093]FIG. 37 is a sectional view showing the completed state, FIG. 38is a cross-sectional view of a seal-up housing showing a fourthpreferred embodiment of the invention,

[0094]FIG. 39 is a longitudinally sectional view showing the entirety ofa seal-up housing, cutting equipment, etc.,

[0095]FIG. 40(a) is a longitudinally sectional view mainly showingcutting equipment before the cutting is started, and

[0096]FIG. 40(b) is a side elevational view of a roughly columnarcutting tool,

[0097]FIG. 41 is a longitudinally sectional view showing the cuttingequipment after the cutting is finished,

[0098]FIG. 42(a), FIG. 42(b), and FIG. 42(c) are, respectively, processviews showing the sequence of slitting,

[0099]FIG. 43 is a longitudinally sectional view showing a state wherethe operation upper chamber is assembled after the cutting is finished,

[0100]FIG. 44 is a sectional view showing a state where the cuttingequipment is removed,

[0101]FIG. 45 is a perspective view showing a valve body and a slitgroove,

[0102]FIG. 46(a) is a side elevational view of rubber packing,

[0103]FIG. 46(b) is a front elevational view of the rubber packing,

[0104]FIG. 46(c) is a longitudinally sectional view showing a closedstate of an existing pipe, and

[0105]FIG. 46(d) is a cross-sectional view showing a closed state of theexisting pipe,

[0106]FIG. 47 is a longitudinally sectional view showing a state wherethe valve body and valve cover of a sluice valve are housed in theoperation upper chamber,

[0107]FIG. 48 is a sectional view showing a state of inserting a valve,

[0108]FIG. 49 is a sectional view showing the completed state,

[0109]FIG. 50(a) is a partially sectioned side elevational view showinga seal-up housing according to a modified version of the fourthpreferred embodiment,

[0110]FIG. 50(b) is a bottom view showing the second split housing,

[0111]FIG. 51(a) is a cross-sectional view showing a state where theseal-up housing is attached to an existing pipe,

[0112]FIG. 51(b) is a plan view of the second split housing,

[0113]FIG. 52 is a longitudinally sectional view showing the completedstate when the valve is open,

[0114]FIG. 53 is a cross-sectional view showing the completed state whenthe valve is open,

[0115]FIG. 54 is a longitudinally sectional view showing the completedstate when the valve is closed,

[0116]FIG. 55 is a cross-sectional view showing the completed state whenthe valve is closed,

[0117]FIG. 56 is a cross-sectional view of the seal-up housing,

[0118]FIG. 57 is a longitudinally sectional view showing the entirety ofthe seal-up housing, cutting equipment, etc.

[0119]FIG. 58(a) is a longitudinally sectional view mainly showing thecutting equipment before the cutting is started,

[0120]FIG. 58(b) is a sectional view of a columnar cutting tool,

[0121]FIG. 59 is a longitudinally sectional view showing the cuttingequipment after the cutting is finished,

[0122]FIG. 60(a), FIG. 60(b), and FIG. 60(c) are, respectively, aprocess view showing the sequence of slitting,

[0123]FIG. 61 is a longitudinally sectional view showing a state afterthe cutting is finished,

[0124]FIG. 62(a), FIG. 62(a), and FIG. 62(a) are, respectively, frontelevational views showing modified versions of the cutting tool, FIG.62(d) is a sectional view showing another method for forming a slitgroove for the piping structure, FIG. 62(e) is a perspective viewshowing still another method for forming a slit groove for the pipingstructure,

[0125]FIG. 63(a) is a cross-sectional view of a seal-up housing showinga fifth preferred embodiment of the invention,

[0126]FIG. 63(b) is a longitudinally sectional view of the same seal-uphousing,

[0127]FIG. 63(c) is a cross-sectional view showing a brief constructionof cutting equipment,

[0128]FIG. 63(d) is a longitudinally sectional view showing a briefconstruction of the cutting equipment,

[0129]FIG. 64 is a sectional view showing the cutting equipment,

[0130]FIG. 65 is a sectional view showing a withdrawing method of thesame cutting equipment,

[0131]FIG. 66(a) is a cross-sectional view showing a method forinserting a sluice valve body, and

[0132]FIG. 66(b) is a longitudinally sectional view showing the samemethod,

[0133]FIG. 67 is a sectional view showing a method for inserting asluice valve body,

[0134]FIG. 68 is a sectional view showing the completed state,

[0135]FIG. 69 is a sectional view showing a valve inserting methodaccording to a modified version of the fifth preferred embodiment,

[0136]FIG. 70 is a sectional view showing a clogging method of thecylindrical portion of the same modified version,

[0137]FIG. 71 is a sectional view showing a seal-up housing according toanother modified version,

[0138]FIG. 72 is a brief sectional view showing a conventional existingpipe cut-off method,

[0139]FIG. 73 is a sectional view showing another conventional method,

[0140]FIG. 74 is a sectional view showing still another conventionalmethod,

[0141]FIG. 75(a) is a sectional view showing a conventional drillingmethod without stopping passage of water, and

[0142]FIG. 75(b) is a sectional view showing a conventional method forinserting a valve in a line without stopping passage of water.

[0143]FIG. 76(a) is a sectional view showing a state before cutting by aconventional valve insertion method for inserting a valve in a linewithout stopping passage of water, and

[0144]FIG. 76(b) is a sectional view after a cutting is completed by theconventional valve insertion method for inserting a valve in a linewithout stopping passage of water,

[0145]FIG. 77 is a sectional view showing a state after a valve isinserted by another conventional valve insertion method for inserting avalve in a line without stopping passage of water,

[0146]FIG. 78 is a longitudinally sectional view showing a state where aseal-up housing is attached,

[0147]FIG. 79 is a cross-sectional view showing a state where a seal-uphousing is attached,

[0148]FIG. 80 is a sectional view showing a state where the cutting toolis attached,

[0149]FIG. 81 is a sectional view showing a state after the cutting iscommenced,

[0150]FIG. 82 is a sectional view showing a state after the cutting iscompleted,

[0151]FIG. 83 is a longitudinally sectional view showing a pipingstructure after a valve is inserted,

[0152]FIG. 84 is a longitudinally sectional view showing a state wherethe valve is closed, and

[0153]FIG. 85 is a cross-sectional view showing a state where the valveis closed.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0154] The invention will be more apparently understood on the basis ofthe following description of preferred embodiments with reference to theaccompanying drawings. However, the preferred embodiments and drawingsare merely for illustration and description. They are not utilized so asto define or limit the scope of the invention. The scope of theinvention is defined on the basis of only the scope of claims attachedhereto. In the accompanying drawings, the same reference numbers in aplurality of drawings indicate the same or equivalent parts.

[0155] First Preferred Embodiment

[0156]FIG. 1 through FIG. 14 show a first preferred embodiment.Hereinafter, a description is given, in the order of processes, of anexisting pipe cut-off method and a method for inserting a valve in aline without stopping passage of water, which are according to the firstpreferred embodiment of the invention. The first embodiment is a methodsuitable for medium- and large-sized pipes ranging from 20 inchesthrough 60 inches in diameter.

[0157] Cutting equipment

[0158] As shown in FIG. 1, a seal-up housing 2 consists of the firsthalf housing 21 and second half housing 22, which are of a semi-splittype, and a cutter attaching housing (tool attaching housing) 23. Asshown in FIG. 2, a pair of left and right seal-up housings 2 and 2 areattached to an existing pipe 1, and they enclose and seal up, in anairtight state, two portions spaced from each other in the axialdirection S of pipe on the existing pipe 1. Rubber rings 24, etc. asshown in FIG. 3 are used to seal between the respective housings 21 and22 and between both the slit housings 21 through 23 and the existingpipe 1. Furthermore, With respect to a sealing structure between theexisting pipe 1 and the respective housings 21 and 22 and between therespective housings 21 and 22, an already known structure disclosed in,for example, FIG. 4 of U.S. Pat. No. 3,650,547 described above may beemployed.

[0159] The abovementioned second split housing 22 has a branch-likeguiding portion (bifurcated portion) 22 a which protrudes from theexisting pipe 1 in its diametrical direction C. The abovementionedcutter attaching housing 23 is attached to the corresponding guidingportion 22 a so that it is slidable in its diametrical direction C. Aslit-like opening 22 b into which a disk-shaped cutting tool 30 isinserted is formed at the guiding portion 22 a in the second slithousing 22.

[0160] Cutting equipment 3 is attached to each of the cutter attachinghousings 23 of a pair of seal-up housings 2. That is, a first motor (oneexample of the prime movers) 31 for rotating a cutting tool is fixedoutside the abovementioned cutter attaching housing 23 while theabovementioned cutting tool 30 is housed in the abovementioned cutterattaching housing 23. A bearing housing 32 is fixed at the cutterattaching housing 23, and a cutter shaft 33 is rotatably supported inthe bearing housing 32 so that the cutter shaft 33 can be driven androtated. The cutting tool 30 is fixed at the cutter shaft 33. The cuttershaft 33 is provided in parallel to the axial direction S of an existingpipe 1. The abovementioned first motor 31 causes the cutting tool 30 torotate via a drive gear 34 fixed at the output shaft 34A of the firstmotor 31, a driven gear 35 fixed at the cutter shaft 33, and theabovementioned cutter shaft 33. Furthermore, a hydraulic motor, apneumatic motor, an oil hydraulic motor or an electric motor may be usedas the abovementioned first motor 31.

[0161] The abovementioned cutting tool 30 is, for example, a diamondwheel.

[0162] The corresponding diamond wheel 30 is such that a number ofdiamond grains 30 c (one example of a number of blades 30 c) are welded,by a YAG laser, to the outer circumferential portion 30 b of adisk-shaped base 30 a shown in FIG. 1(b) together with metallic powder.A number of blades 30 c are provided on the outer circumferentialsurface and both side surfaces of the base 30 a. Although thecorresponding diamond wheel 30 is a cutting tool, havingnon-directivity, which is able to slit an existing pipe 1 even though itrotates in any one of two directions centering around the cutter shaft33 in FIG. 1(a), it is preferable that the cutter shaft 33 is caused torotate in the rotation direction Al opposite to the rotation direction Rof the seal-up housing 2 in FIG. 1(a). This is because cutting chips arescarcely discharged into the existing pipe 1 during slitting.

[0163] The abovementioned diamond wheel 30 is suitable for cuttingconcrete and stone materials. As for the corresponding diamond wheel,those made by Robtex, Ltd. and/or Shibaura Mfg. CO., Ltd. may be used.

[0164] Furthermore, a mechanical seal (not illustrated) is used to sealbetween the bearing housing 32 and the cutter shaft 33.

[0165] A cutting feed frame 36 is fixed at the above-mentioned guidingportion 22 a. The cutting feed frame 36 is provided with long bolts 36 afixed at the abovementioned guiding portion 22 a and a top plate 36 bfixed at the upper ends of the long bolts 36 a. A male lead screw 37 forcutting feed is screwed in a bushing 36 c secured at the top plate 36 bof the abovementioned cutting feed frame 36. By turning the male leadscrew 37 for cutting feed to be screwed in the cutting direction C (thecenter direction of the diametrical direction C of an existing pipe 1),the cutter attaching housing 23 advances in the cutting direction C.Therefore, the cutter attaching housing 23 is fed in the cuttingdirection C while rotating the above-mentioned cutting tool 30, whereinif the cutting tool 30 is caused to advance in a slit-like opening 22 bin FIG. 3, the cutting tool 30 is fed toward roughly the center in thediametrical direction of the existing tube 1, thereby causing theexisting pipe 1 to be slit as shown in FIG. 4.

[0166] As shown in FIG. 2, a housing turning device 4 is disposedbetween the abovementioned pair of seal-up housings 2 and 2. Thecorresponding housing turning device 4 has an annular spacer 40circumferentially divided into two sections. The corresponding spacer 40is to determine the relative position between a pair of seal-up housings2 and 2. The spacer 40 is fixed at the existing pipe 1 with a number ofset screws 46 and a liner 41 is provided at both sides of the spacer 40.

[0167] A gear housing 43 is fixed at one of the above-mentionedtwo-split spacers 40, and a second motor 42 for turning the seal-uphousing is fixed at the corresponding gear housing 43. The correspondingsecond motor rotates a pair of drive gears 44 for turning the seal-uphousing, via a bevel gear 47 and a driven gear 47A, etc., and therespective drive gears 44 rotates a driven gear 45 for turning theseal-up housing, which is fixed at the outer circumference of the firstand second split housings 21 and 22. Therefore, the present method isable to cut off an existing pipe 1 at two points by turning the seal-uphousing 2 once around the existing pipe 1 while causing the cutting tool30 to rotate in a cutting feed state shown in FIG. 4 (that is, carryingout a slitting motion).

[0168] As shown in FIG. 2, an annular slip preventing member 5 is,respectively, secured at the existing pipe 1 outward of theabovementioned pair of seal-up housings 2 and 2. The corresponding slippreventing member 5 is divided into two sections in the circumferentialdirection R (FIG. 1) of the existing pipe 1, and the slip preventingmember 5 is provided with a number of steel balls 50 and set screws 51secured alternately in the circumferential direction R (FIG. 1). Theslip preventing member 5 is fixed at the existing pipe 1 by set screws51. The slip preventing member 5 presses the seal-up housing 2 to thecentral side by the steel balls 50 and nips the seal-up housing 2between the steel balls 50 and the liners 41 of the abovementionedhousing turning device 4, wherein the seal-up housing 2 is preventedfrom slipping and shaking in the axial direction S of the existing pipe1. Therefore, the seal-up housing 2 smoothly turns when turning aroundthe existing pipe 1. Furthermore, the abovementioned steel balls 50 arefixed at the slip preventing member 5 so that their positions are ableto be adjusted in the axial direction S of pipe 1 in FIG. 3.

[0169] A bar-like valve 25 is secured at the slit-like opening 22 b ofthe abovementioned second split housing 22 in FIG. 3. As shown in FIG.5(a), the corresponding bar-like valve 25 is provided with a bar-likelong valve body 26 and a bar-like valve housing 27. As shown in FIG.5(b) and FIG. 5(c), the abovementioned bar-like valve body 26 iscomposed so that half-moon type rubber packing 26 b is formed integralwith a metallic core 26 a, and so that the valve body 26 is rotatablyattached to the bar-like valve housing 27. The bar-like valve body 26allows the cutting tool 30 to be fed for cutting as shown in FIG. 5(b),and on the other hand, seals the slit-like opening 22 b to stop water byturning the bar-like valve body 26 as shown in FIG. 5(c) after thecutting is finished.

[0170] Cutting Process

[0171] Next, a description is given of a cutting procedure.

[0172] First, workmen attach a housing turning device 4 and a spacer 40to the existing pipe 1 in a state where fluid (water) is flowing throughthe existing pipe 1 in FIG. 2, and attach a seal-up housing 2 and slippreventing members 5 to both sides of the housing turning device 4,wherein two points spaced from each other in the axial direction S ofthe pipe on the existing pipe 1 are enclosed and sealed up in anairtight state by a pair of seal-up housings 2 and 2. Cutting equipment3 is attached, in advance, to a cutter attaching housing 23 of theseal-up housing 2. Furthermore, the workmen fix a bar-like valve 25 byturn-stop bolts 26 c in FIG. 5(a) in its open state as shown in FIG.5(b).

[0173] Next, as the workmen drive the first motor 31 in FIG. 3, thecorresponding first motor 31 rotates the above-mentioned cutting tool 30on the cutter shaft 33 at a high speed and causes the cutting tool 30 toperform a slitting motion by which the existing pipe 1 is slit byrotations of the cutting tool 30. In a state where the correspondingslitting motion is being carried out by the cutting tool 30, as theworkmen progressively screw a male lead screw 37 for cutting feed in thecutting direction C, the cutting tool 30 advances, concurrently, to theposition where the cutting tool 30 passes through a part of the wall laof the existing pipe 1 as shown with alternate long and two dashes linesin FIG. 1. Thus, cutting feed of the cutting tool 30 in the direction Cis completed.

[0174] After that, as workmen drive the second motor for turning theseal-up housing in FIG. 2, a pair of seal-up housings 2 are turnedaround the existing pipe 1 via a bevel gear 47 and a pair of drive gears44 and driven gear 45. Thereby, the cutting tool 30 in FIG. 1 is causedto rotate on the cutter shaft 33 while the cutting tool 30 turns in thedirection of the arrow R along the outer circumference of the existingpipe 1 together with the seal-up housings 2, wherein the cutting tool 30roughly slits annularly the existing pipe 1, and finally cuts off thepipe 1. That is, with the second motor 42 in FIG. 2, the cutting tool 30in FIG. 4 is turned in the circumferential direction R by turning theabovementioned seal-up housing 2 in the circumferential direction R(FIG. 1) of the existing pipe 1, wherein the cutting tool 30 is causedto perform a feeding motion. Thereby, the cutting tool 30 cuts off theexisting pipe 1, and a cut-off section 10 to be removed (a cylindricalcut-off section 10 in FIG. 6) in FIG. 4 is formed from the existing pipe1. After the cutting-off, the workmen reversely turn the male lead screw37 for cutting feed, cause the cutting tool 30 to slide together withthe cutter attaching housing 23, and retreat the cutting tool 30 to anon-cutting position in FIG. 3.

[0175] After the cutting tool is retreated, the workmen turn thebar-like valve body 26 in FIG. 5(b) by 90 degrees, wherein the fluid(water) is prevented from flowing out through the slit-like opening 22 bin FIG. 5(c). The next eliminating process of the cut-off section iscommenced after the sealing is finished.

[0176] Cut-Off Section Eliminating Process

[0177] After the cutting off is completed, the workmen remove thecutting equipment 3 from the existing pipe 1 in FIG. 2 together with thecutting attaching housing 23. Furthermore, the workmen remove the slippreventing members 5, housing turning device 4, spacer 40, etc., fromthe existing pipe 1. Thus, as shown in FIG. 6, the situation is suchthat the existing pipe 1 is in a state where only a first split housing21, second split housing 22 of the seal-up housing 2 and bar-like valve25 remain. After that, the workmen fixes a lifting band 11 to thecut-off section 10 in order to raise the cut-off section 10 between bothseal-up housings 2 and 2, and at the same time attach a split type shortpipe 6 to both sides of the seal-up housings 2 and 2 at the existingpipe 1. The split type short pipe 6 is divided into two sections in thecircumferential direction R (FIG. 1) of the existing pipe 1, and isprovided with a packing insertion portion 60, into which rubber packingis inserted, and a plate-like flange 61, which compresses sheet packing81 (FIG. 12), at both ends thereof. Furthermore, the corresponding splittype short pipe 6 is provided with an O ring 63 to temporarily stopwater in a groove 62.

[0178] Next, as shown in FIG. 7, the workmen enclose and seal up, in anairtight state, both seal-up housings 2 and 2 and split type short pipe6 together with the existing pipe 1 by an operation chamber 7, andconnect an elevating shaft 76 to the lifting band 11. The operationchamber 7 consists of operation lower chambers 71 and 72, which aredivided in the perpendicular direction (circumferential direction), anoperation sluice valve 73 and an operation upper chamber 74. On theother hand, the workmen screw a pressing rod 75, by which the split typeshort pipe 6 and seal-up housing 2 are caused to slide, into theoperation lower chambers 71 and 72 before sealing up by theabovementioned operation chamber 7 and connect the tip end of thepressing rod 75 to the split type short pipe 6 via a connecting metalfitting 75 a in FIG. 8. The corresponding pressing rod 75 consists of,for example, a male long screw. The workmen turns the pressing rod 75clockwise to move the split type short pipe 6 to the central side. Onthe other hand, by turning the pressing rod 75 counterclockwise, thesplit type short pipe 6 is returned sideways.

[0179] In a state as shown in FIG. 8, if workmen turn the pressing rod75 clockwise, the split type short pipe 6 is pressed and is caused toslide to the central side, wherein the split type short pipe 6 pressesthe seal-up housing 2 to cause the split type short pipe 6 to move tothe central side. After the seal-up housing 2 rides over the cut-offgroove portion 12 and is placed on the cut-off section 10, the workmenreversely turn the pressing rod 75, only the split type short pipe 6 isreturned sideways (right side) as shown in FIG. 9. Thereafter, theworkmen lift up the elevating shaft 76 and take out the cut-off section10 together with two seal-up housings 2 and 2 from the operation lowerchambers 71 and 72 to the operation upper chamber 74 in FIG. 10, whereinan operation sluice valve 73 is closed. After the sluice valve 73 isclosed, workmen remove the cut-off section 10 and seal-up housing 2together with the operation upper chamber 74. Furthermore, the workmenmay use a lifting device such as a crane in assembling theabovementioned chamber 74.

[0180] Furthermore, in FIG. 7, FIG. 9, FIG. 11, or FIG. 13, theabovementioned O-ring 63 (FIG. 12) for temporarily stopping water isomitted.

[0181] Process for Inserting a Valve

[0182] After the cut-off section 10 is eliminated in FIG. 10, as shownin FIG. 11, workmen houses a valve for insertion such as a butterflyvalve 8 in an operation upper chamber 74. The butterfly valve 8 hascollar-like flanges 80 and 80 at both ends, and for example, annularsheet packing 81 is cemented to the respective flanges 80 and 80.Furthermore, when inserting the corresponding butterfly valve 8, thebutterfly valve 8 is kept in its open state and a speed reducer 82 (FIG.14) is removed from the butterfly valve 8.

[0183] After that, the workmen open the operation sluice valve 73. Afterthe valve is opened, the butterfly valve 8 is shifted down into theoperation lower chambers 71 and 72. Thereafter, as the pressing rod 75in FIG. 12 is turned clockwise by workmen and the split type short pipe6 is caused to slide toward the butterfly valve 8, as shown in FIG. 13,a plate-like flange 61 of the split type short pipe 6 is brought intocontact with the sheet packing 81 concurrently. In this state, the sheetpacking 81 is compressed between the two plate-like flanges 61 and 80 byan axial force of the pressing rod 75, wherein it is attempted thatwater is temporarily stopped between the split-type short pipe 6 andbutterfly valve 8. On the other hand, water is also temporarily stoppedbetween the split-type short pipe 6 and the existing pipe 1 by theabovementioned O-ring 63 mounted in advance at the split-type short pipe6 in FIG. 14.

[0184] Thereafter, workmen discharge water in the operation chamber 7 inFIG. 13. After water is discharged, the workmen tighten a pair ofplate-like flanges 61 and 80 by tightening bolts 83 in FIG. 14, whereinwater is completely stopped between the split type short pipe 6 andbutterfly valve 8. After that, the workmen disassemble the operationchamber 7 in FIG. 13. After the disassembling is completed, the workmenattach split-type pressing rings 65 between the existing pipe 1 and thesplit-type short pipes 6 and press water stopping rubber rings 64 intothe abovementioned packing inserting portions 60 of the split-type shortpipe 6. On the other hand, a speed reducer 82 is attached to thebutterfly valve 8. Thus, the butterfly valve 8 which stops water in aline 1A is inserted into the line 1A including the existing pipe 1.

[0185] Thus, in the present cut-off method, since the abovementionedcutting tool 30 is turned in the outer circumference of the existingpipe 1 by turning the seal-up housing 2 when cutting it off in FIG. 2,it is not necessary that a mechanism for turning the cutting tool 30around the existing pipe 1, that is, a housing turning device 4 isprovided in the seal-up housing 2. Therefore, downsizing of the seal-uphousing 2 is achieved. Furthermore, with a valve inserting methodaccording to the invention, although an operation chamber 7 in FIG. 7 isrequired and the corresponding operation chamber 7 is remarkably largein comparison with the seal-up housing 2, the operation chamber 7 ismade smaller than that in prior arts since the seal-up housing 2 fromwhich the cutting equipment 3 is removed is accommodated by theoperation chamber 7.

[0186] Hence, in the abovementioned preferred embodiment, although adiamond wheel 30 in FIG. 1(a) is used as the abovementioned cuttingtool, an end mill 30 in FIG. 15(a) and a metal slitting saw 30B shown inFIG. 15(c) may be used in the invention instead of a disk-shaped cuttingtool 30. The abovementioned metal slitting saw 30B in FIG. 15(c) iscomposed so that a number of cutting chips (blades) 30 h are brazed tothe outer circumferential portion of a disk-shaped base 30 g.

[0187] Furthermore, instead of turning the bar-like valve body 26 in thepreferred embodiment, a plate-like valve body 26A in FIG. 15(b) may beinserted into a slit-like opening 22 b in FIG. 15(a) to cause water tobe stopped by clogging the opening 22 b. Furthermore, with the methodfor inserting a valve in a line without stopping water according to theinvention, a sluice valve may be inserted instead of a butterfly valve.

[0188]FIG. 16 shows a modified version of the first preferredembodiment.

[0189] In the modified version of the first embodiment, a cutterattaching housing 23A is rotatably attached to the second split housing22A via a hinge 38. The corresponding cutter attaching housing 23A isfixed at the second split housing 22A by bolts 39.

[0190] In the modified version, in order to cut off the existing pipe 1,first, the workmen attach the second split housing 22A, etc., to theexisting pipe 1. Subsequently, the workmen actuate the first motor 31 torotate the cutting tool 30 in a state where the cutter attaching housing23A is open as shown with an alternate long and two dashes line in FIG.16(a). From this state, the workmen cause the cutter attaching housing23A in the direction of the arrow around the hinge 38, the cutting tool30 also moves in the direction of the arrow and begins cutting off theexisting pipe 1. Concurrently, as the cutter attaching housing 23Aenters a state where the the slit-like opening 22 b of the second splithousing 22A, the cutting tool 30 finishes a cutting feed of the existingpipe 1. Thereafter, the workmen fix the cutter attaching housing 23A atthe second split housing 22A by bolts 39 in FIG. 16(a). After the cutterattaching housing 23A is fixed, the existing pipe 1 is cut off if theworkmen turn the seal-up housing 2 around the existing pipe 1 whileproviding a slitting motion to the cutting tool 30.

[0191] Second Preferred Embodiment

[0192]FIG. 17 through FIG. 25 show a second preferred embodiment.

[0193] Hereinafter, a description is given, in the order of processes,of an existing cut-off method and a method for inserting a valve in aline without stopping passage of water according to the second preferredembodiment. The following embodiments including the second preferredembodiment are suitable for and applicable to small- and medium-sizedpipes having a diameter of 4 inches through 20 inches.

[0194] Cutting Equipment

[0195] As shown in FIG. 18, in the preferred embodiment, a central firstseal-up housing 2A and a pair of left and right second seal-up housings2B are used. The abovementioned first seal-up housing 2A is providedwith a first split housing 121 and a second split housings 122, dividedinto two sections in the circumferential direction R as shown in FIG.17, and a two-cutting tool attaching housing 123. Furthermore, theabovementioned second seal-up housing 2B (FIG. 18) is also divided intotwo sections in the circumferential direction. Rubber rings 124, etc.,are used to seal between these housings 121 and 122, and 2A and 2B, andbetween the second seal-up housing 2B and the existing pipe 1 in FIG.19.

[0196] The abovementioned second split housing 122 has a bifurcatedportion 122 b protruding outward in the diametrical direction C of theexisting pipe 1. The cutter attaching housing 123 is slidably attachedto the bifurcated portion 122 b in the diametrical direction C of theexisting pipe 1 via a guide bushing 122 a so that the cutter attachinghousing 123 is permitted to advance and retreat. An opening 122C intowhich two disk-shaped cutting tools 130 are inserted is formed at theabovementioned bifurcated portion 122 b at the second split housing 122.

[0197] Cutting equipment 3 is attached to the cutter attaching housing(tool attaching housing) 123 of the first seal-up housing 2A. That is, afirst motor (one example of a prime mover) 131 for rotating the tools isfixed upward of the abovementioned cutter attaching housing 123. On theother hand, the abovementioned two cutting tools 130 are disposed in theabovementioned cutter attaching housing 123. It is preferable that adiamond wheel having the same structure as that of the first preferredembodiment is used as the corresponding cutting tool 130. These cuttingtools 130 are disposed so as to be spaced from each other in the axialdirection S of pipe 1 and are fixed at the cutter shaft 133. The cuttershaft 133 is rotatably supported at a bearing housing 132 fixed at thecutter attaching housing 123 so that it is able to be driven androtated. The first motor 131 causes the cutting tools 130 to rotate viathe output shaft of the first motor 131, a bevel gear 134 attached tothe cutter shaft, and the cutter shaft 133.

[0198] A cutting feed frame 136 is fixed at the bifurcated portions 122b, and the corresponding cutting feed frame 136 is provided with longbolts 136 a fixed at the bifurcated portions 122 b and a top plate 136 bfixed at the upper ends of the long bolts 136 a. A cutting feed malelead screw 137 is screwed in a bushing 136 c secured at the top plate136 b of the cutting feed frame 136.

[0199] By turning and screwing the abovementioned cutting feed male leadscrew 137 in the cutting feed direction C, the cutter attaching housing123 advances in the cutting feed direction C. Therefore, the cutterattaching housing 123 is sent in the cutting feed direction C to causethe cutting tools 130 to go into the opening 122C while rotating thecutting tools 130, wherein as shown in FIG. 20, it is possible to slitthe existing pipe 1 by the abovementioned cutting tools 130.Furthermore, since the guide bushing 122 a is fixed at the top plate 136b via a connection metal fitting 138 in FIG. 17, it is collectedtogether with the cutting feed frame 136 after the cutting is completed.

[0200] As shown in FIG. 17, a lifting belt 11A is wound onto theexisting pipe 1 and cutter shaft 133, by which a freshly cut-off section10 in FIG. 21 is collected together with the cutting equipment 3 aftercutting off the existing pipe 1. Furthermore, the lifting belt 11A issuch that as in FIG. 17, a flexible rubber plate portion 11 a, a thinmetal belt 11 b, and a connection piece 11 c are united.

[0201] In the preferred embodiment, a housing turning device 4 shown inFIG. 18 is provided, which causes the first seal-up housing 2A to beturned around the existing pipe 1. The housing turning device 4 has apair of second motors 142 for turning the seal-up housing. Thecorresponding second motors 142 rotates drive gears 144, which turn theseal-up housing, via the respective output shafts 147. The correspondingdrive gears 144 driven gears 145, which turns the seal-up housing fixedat the first seal-up housing 2A. Therefore, by turning the first seal-uphousing 2A to be turned around the existing pipe 1 once while rotatingthe cutting tools 130 in a cutting feed state as shown in FIG. 20, theexisting pipe 1 can be cut off at two points.

[0202] As shown in FIG. 19, the second seal-up housing 2B constitutes aslip preventing member 5A. The corresponding second seal-up housing 2Bis divided into two divisions in the circumferential direction R (FIG.17). The second seal-up housing 2B has a number of set screws 151provided in the circumferential direction R (FIG. 17) at each of the twopoints spaced from each other in the axial direction S of pipe 1. Arotation guiding portion 150 which slides via a liner 152 is provided atthe connection portion between the first seal-up housing 2A and thesecond seal-up housing 2B. The second seal-up housing 2B is fixed at theexisting pipe 1 by the abovementioned set screws 151. The abovementionedpair of second seal-up housings 2B guides the first seal-up housing 2Avia the above-mentioned rotation guiding portion 150 and prevents thefirst seal-up housing 2A from slipping or shaking in the axial directionS of the existing pipe 1. Therefore, the first seal-up housing 2A isable to be smoothly turned when turning around the existing pipe 1.Furthermore, a ball bearing may be used instead of the liner 152.

[0203] Cutting Process

[0204] Next, a description is given of a cutting process.

[0205] First, in a state where fluid (water) is flowing through theexisting pipe 1 in FIG. 17, the workmen apply the upper half member ofthe first and second seal-up housings 2A and 2B (in FIG. 18) onto theexisting pipe 1, and wind the lifting belt 11A onto the cutter shaft 133and existing pipe 1. Thereafter, the workmen tighten the lower halfmember of the first and second seal-up housings 2A and 2B together withthe upper half member by assembly bolts 128. Thus, the existing pipe 1is enclosed and sealed up, in an airtight state, by the first and secondseal-up housings 2A and 2B. Furthermore, the workmen attach, in advance,the cutting equipment 3 to the cutter attaching housing 123 of the firstseal-up housing 2A.

[0206] Next, as the workmen drive the first motor 131 in FIG. 19, thecorresponding first motor 131 rotates the abovementioned cutting tools130 on the cutter shaft 133 at a high speed, wherein the abovementionedcutting tools 130 are caused to perform a slitting motion by which theexisting pipe 1 is slit by rotations of the corresponding cutting tools130. In the state where the cutting tool 130 is performing thecorresponding slitting motion, if the workmen screws the male lead screw137 for cutting feed in the direction C, concurrently, theabovementioned cutting tools 130 advance, as shown with an alternatelong and two dashes line in FIG. 17, to the position where the cuttingtools 130 pass through a part of the wall la of the existing pipe 1.Thus, cutting feed of the cutting tools 130 in the direction C iscompleted.

[0207] After the cutting feed, if the workmen drive the second motor 142for turning the seal-up housing, the first seal-up housing 2A is turnedaround the existing pipe 1 via a pair of drive gears 144 and drivengears 145 in FIG. 20, in a state where the first seal-up housing 2A isguided by the second seal-up housing 2B. Thereby, the cutting tools 130shown in FIG. 17 are rotated on the cutter shaft 133 while turning inthe direction of the arrow R along the outer circumference of theexisting pipe 1 together with the first seal-up housing 2A, wherein asshown in FIG. 21, the existing pipe 1 is slit to be roughly annular attwo points to cut off the existing pipe 1. That is, the abovementionedsecond motor 142 shown in FIG. 18 causes the cutting tools 130 in FIG.20 to turn in the circumferential direction R by turning the firstseal-up housing 2A in the circumferential direction R (FIG. 17) of theexisting pipe 1, thereby causing the cutting tools 130 to perform afeeding motion. Therefore, the cutting tools 130 cut off theabovementioned existing pipe 1.

[0208] After the corresponding cutting is completed, the workmen removethe housing turning device 4 (in FIG. 18).

[0209] Furthermore, cutting chips may be discharged through a waterdischarge valve by attaching the discharge valve to the cutter attachinghousing 123.

[0210] Cut-Off Section Removing Process

[0211] Next, the workmen remove the cutting equipment 3 and freshlycut-off section 10 by the method described below. As shown in FIG. 21,the workmen connect an operation sluice valve 173 to the bifurcatedportion 122 b and further connect an operation upper chamber 174 to theabovementioned operation sluice valve 173 so as to overlap thereon. Atthe point of the connection, the workmen connect a cutting feed frame136 to the tip end of an lifting shaft 176 passing through the operationupper chamber. After the connection is completed, the workmen removenuts 139. After removing the nuts, the workmen raise the lifting shaft176 in FIG. 22 to remove the cutting equipment 3 and cut-off section 10from the first seal-up housing 2A into the operation upper chamber 174.After that, the operation sluice valve 173 is closed. After the valve isclosed, the workmen separate the operation upper chamber 174 from theoperation sluice valve 173.

[0212] Valve Inserting Process

[0213] Next, the workmen accommodate a valve cover 8 b in FIG. 23 andsluice valve body 8 a into the operation upper chamber 174 and connectthe operation upper chamber 174 to the operation sluice valve 173. Thesluice valve 8A is provided with a spindle 8 c for opening and closingthe sluice valve body 8 a. The sluice valve 8A constitutes a valve sothat, if the spindle 8 c is turned, the sluice valve body 8 a invadesthe cut-open portion 12B and rubber packing 8 d secured at the sluicevalve body 8 a is pressure-fitted to the inner circumferential portions,etc., of the first seal-up housing in FIG. 25.

[0214] After the operation upper chamber 174 shown in FIG. 23 isattached, the workmen open the operation sluice valve 173 as shown inFIG. 24 and lower the lifting shaft 176. Thereby, the valve cover 8 b isbrought into contact with the bifurcated portion 122 b. After they arebrought into contact with each other, the workmen connect the valvecover 8 b to the bifurcated portion 122 b by flange bolts 8 e. After theconnection is completed, the workmen withdraw the operation upperchamber 174 and operation sluice valve 173. Thereafter, the workmenpress rubber rings 164 into the packing insertion portions 160 of thesecond seal-up housing 2B in FIG. 25 and attach the split press rings165 to the second seal-up housing 2B. Thus, the sluice valve 8A isdisposed at the position corresponding to the cut-open portion 12B andthe sluice valve 8A is inserted into a line 1A.

[0215]FIG. 26 through FIG. 28 show a modified version of the embodiment.

[0216] As shown in the modified version, the lifting belt 11A may beattached to the bifurcated portion 122 b. Furthermore, as shown in FIG.27, the output of the first motor 131 may be transmitted to the cuttershaft 133 via a timing belt 135. Moreover, at the point of cutting shownin FIG. 28, a guide roller 146 which bites the outer surface of theexisting tube 1 and guides the cutting equipment 3 may be provided.Furthermore, the cutter shaft 133 is rotatably supported at an eye bolt133A.

[0217] Third Preferred Embodiment

[0218]FIG. 29 through FIG. 37 show a third preferred embodiment.

[0219] Hereinafter, a description is given, in the order of processes,of an existing pipe cut-off method and a method for inserting a valve ina line without stopping passage of water according to the thirdpreferred embodiment.

[0220] Cutting Equipment

[0221] As shown in FIG. 30, in the preferred embodiment, a first centralseal-up housing 2A and a pair of left and right second seal-up housings2B are used. The first seal-up housing 2A is equipped with, as shown inFIG. 29, the first and second split housings 221 and 222, which aresplit into two sections in the circumferential direction, and a guidebushing 222 a. Furthermore, the above-mentioned second seal-up housing2B (FIG. 30) is divided into two divisions. As shown in FIG. 31(a),rubber rings 224, etc. are used to seal up between these housings 221and 222, and 2A and 2B, and the second seal-up housing 2B and theexisting pipe 1.

[0222] The abovementioned second split housing 222 has a bifurcatedportion 222 b protruding from the existing pipe 1 in the diametricaldirection C. A main bearing (tool attaching housing) 232 is secured atthe bifurcated portions 222 b via the abovementioned guide bushing 222 aso that the main bearing is able to slidably be advanced and retreatedin the diametrical direction C of the existing pipe 1. Rubber rings 224are used to seal up between the abovementioned guide bushing 222 a,bifurcated portions 222 b and main bearing 232. An opening 222 c intowhich an end mill (cutting tool) 230 is inserted is formed at theabovementioned bifurcated portions 222 b at the second split housing222.

[0223] Cutting equipment 3 is attached to the guide bushing 222 a fixedat the abovementioned first seal-up housing 2A via the main bearing 232.That is, the first motor 231 (an example of a prime mover) for rotatinga tool is fixed upward of the main bearing 232. On the other hand, theabovementioned end mill 230 is disposed inside the abovementioned mainbearing 232. The end mill 230 is formed integral with the main shaft 233(cutter shaft) rotatably supported on the main bearing 232. The firstmotor 231 rotates the end mill 230 via the output shaft 231 a of thefirst motor 231 and a coupling 234 fixed at the main shaft 233.

[0224] As shown in FIG. 31(b), the abovementioned end mill 230 isprovided with a plurality of blades 230 f at the columnar tip endsurface 230 d and the outer circumferential surface 230 e thereof.Furthermore, the abovementioned main shaft 233 is formed at the end mill230 integral therewith. As shown in FIG. 29, the axial line 233 a of theabovementioned end mill 230 and main shaft 233 is set in the diametricaldirection C of the existing pipe 1. The abovementioned end mill 230carries out a slitting motion by rotating around the axial line 233 aestablished in the diametrical diameter C of the above-mentionedexisting pipe 1.

[0225] A cutting feed frame 236 is fixed at the above-mentionedbifurcated portions 222 b in FIG. 31(a). The cutting feed frame 236 isprovided with long bolts 236 a fixed at the abovementioned bifurcatedportions 222 b and a top plate 236 b fixed at the upper end of thecorresponding long bolts 236 a. A mail lead screw 237 for cutting feedis screwed in a bushing 236 c secured at the above-mentioned top plate236 b of the abovementioned cutting feed frame 236.

[0226] By turning and screwing the corresponding male lead screw 237 forcutting feed in the cutting feed direction C, the main bearing 232advances in the cutting feed direction C. Therefore, by feeding the endmill 230 together with the main bearing 232 in the cutting feeddirection C while rotating the end mill 230 and causing the end mill 230to advance into the opening 222 c, it is possible to slit the existingpipe 1 by the end mill 230 as shown in FIG. 32. Furthermore, the guidebushing 222 a is fixed at the cutting feed frame 236 via a connectionmetal fitting 238 in FIG. 29, and it is designed so that it can becollected together with the cutting feed frame 236 after the cutting iscompleted.

[0227] In the preferred embodiment, a housing turning device 4, shown inFIG. 30, which causes the first seal-up housing 2A to rotate around theexisting pipe 1, is provided. The housing turning device 4 has a pair ofsecond motors 242 for turning the seal-up housing. The correspondingsecond motors 242 rotate drive gears 244 for turning the seal-up housingvia their output shafts 247. The corresponding drive gears 244 rotatedriven gears 245 for turning the seal-up housing, which are fixed at thefirst seal-up housing 2A. Therefore, by causing the first seal-uphousing 2A to turn once around the existing pipe 1 while rotating theend mill 230 in a cutting feed state in FIG. 32, it is possible to cutoff the existing pipe 1.

[0228] As shown in FIG. 31, the second seal-up housing 2B constitutes aslip preventing member 5A. The corresponding second seal-up housing 2Bis divided into two sections in the circumferential direction R (FIG.29) of the existing pipe 1. A number of set screws 251 are secured attwo points spaced from each other in the axial direction S of pipe 1 atthe corresponding second seal-up housing 2B, in the circumferentialdirection R (FIG. 29). A rotation guiding portion 250 which slides via aliner 252 is provided at the connection portion between the firstseal-up housing 2A and the second seal-up housing 2B. The abovementionedpair of second seal-up housings 2B are fixed at the existing pipe 1 bythe set screws 251. The abovementioned second seal-up housings 2B guidethe first seal-up housing 2A via the abovementioned rotation guidingportion 250 and prevent the first seal-up housing 2A from slipping orshaking in the axial direction S of the existing pipe 1. Therefore, thefirst seal-up housing 2A is able to be smoothly turned when turningaround the existing pipe 1. Furthermore, a ball bearing may be usedinstead of the liner 252.

[0229] Cutting Process

[0230] Next, a description is given of a sequence of cutting.

[0231] First, the workmen attach the first and second seal-up housings2A and 2B to the existing pipe 1 in a state where fluid (water) isflowing through the existing pipe 1 in FIG. 30, and assemble both splithousings 221 and 222 by assembling bolts 228 in FIG. 29. Thus, as shownin FIG. 30, the first and second seal-up housings 2A and 2B enclose andseal up the existing pipe 1 in an airtight state. Furthermore, thecutting equipment 3 is attached, in advance, to the guide bushing 222 aof the first seal-up housing 2A.

[0232] Next, as the workmen drive the first motor 231 in FIG. 29, thecorresponding first motor 231 causes the end mill 230 to rotate aroundthe axial line 233 a of the main shaft 233 and causes the cutting tool230 to perform a slitting motion by which the existing pipe 1 is slit byrotations of the end mill 230. In a state where the correspondingcutting tool 230 is performing a slitting motion, if the workmen screwthe male lead screw 237 for cutting feed in the cutting feed directionC, concurrently, the tip end face 230 d of the end mill 230 (FIG. 31(b))advances to the position where it passes through a part of the wall laof the existing pipe 1. Thus, the cutting feed of the end mill 230 inthe direction C is completed.

[0233] After that, the workmen drive the second motor 242 for turningthe seal-up housing in FIG. 30, the first seal-up housing 2A is turnedaround the existing pipe 1 via a pair of drive gears 244 and drivengears 245 in FIG. 32 in a state where it is guided by the second seal-uphousing 2B. Thereby, the end mill 230 rotates on the main shaft 233while turning in the outer circumference of the existing pipe 1 togetherwith the first seal-up housing 2A, wherein, by slitting the existingpipe 1 roughly annularly, the existing pipe 1 is cut off.

[0234] That is, the abovementioned second motor 242 (FIG. 29) causes theend mill 230 to be turned in the circumferential direction R (FIG. 29)by turning the abovementioned first seal-up housing 2A in theabovementioned circumferential direction R of the existing pipe 1 inorder to perform a feed motion of the end mill 230, wherein the end mill230 annularly slits the existing pipe 1 and cuts off the above-mentionedexisting pipe 1. After the cutting is completed, the workmen remove thehousing turning device 4 in FIG. 30.

[0235] Furthermore, if a water discharge valve is attached to the mainbearing 232, cutting chips may be discharged through the water dischargevalve when carrying out a slitting motion.

[0236] Cutting Equipment Removing Process

[0237] Next, the workmen remove the cutting equipment 3 by the methoddescribed below. That is, as shown in FIG. 33, the operation sluicevalve 273 is connected to the bifurcated portion 222 b, and furthermorean operation upper chamber 274 is connected to the operation sluicevalve 273 so as to overlap thereon. When connecting them, the workmenconnect a cutting feed frame 236 to the tip end portion of a liftingshaft 276 which passes through the the operation upper chamber 274.After the connection is finished, the workmen remove nuts 239. After thenuts are removed, the workmen raise the lifting shaft 276 in FIG. 34 andremove the cutting equipment 3 from the first seal-up housing 2A intothe operation upper chamber 274. After the cutting equipment 3 isremoved, the workmen close the operation sluice valve 273. After thevalve is closed, the workmen separate the operation upper chamber 274from the operation sluice valve 273.

[0238] Valve Inserting Process

[0239] Next, the workmen accommodate the valve cover 8 b in FIG. 35 andthe sluice valve body 8 a in the operation upper chamber 274 and connectthe corresponding upper chamber 274 to the operation sluice valve 273.The sluice valve 8A is provided with a spindle 8 c for opening andclosing the sluice valve body 8 a. The sluice valve 8A constitutes avalve so that rubber packing 8 d secured at the sluice valve body 8 a ispressure-fitted to the inner circumferential surface, etc. of the firstseal-up housing 2A in FIG. 37 as the sluice valve body 8 a invades thecut-open portion 12 by turning the spindle 8 c. That is, the firstseal-up housing 2A constitutes a valve housing of the sluice valve 8A.

[0240] After the operation upper chamber 274 in FIG. 35 is mounted, theworkmen open the operation sluice valve 273 as shown in FIG. 36 andshift down the lifting shaft 276, wherein the valve cover 8 b is broughtinto contact with the bifurcated portion 222 b. After they are broughtinto contact with each other, the workmen connect the valve cover 8 b tothe bifurcated portion 222 b by flange bolts 8 e. After the connectionis finished, the workmen withdraw the operation upper chamber 274 andoperation sluice valve 273. Thereafter, the workmen press rubber rings264 into the packing insertion portions 260 of the second seal-uphousing 2B in FIG. 37 and attach the split press rings 265 to the secondseal-up housings 2B. Thus, the sluice valve 8A is disposed at theposition corresponding to the cut-open portion 12, and the sluice valve8A is inserted in a line.

[0241] Fourth Preferred Embodiment

[0242]FIG. 38 through FIG. 49 show a fourth preferred embodiment.

[0243] Hereinafter, a description is given, in the order of processes,of an existing pipe slitting method and a method for inserting a valvein a line without stopping passage of water according to the fourthpreferred embodiment. Cutting equipment and fixtures for operation,which are used in the fourth preferred embodiment, are almost the sameas those in the third preferred embodiment. However, in order to makethem doubly sure, their description is given below.

[0244] Cutting Equipment (Slitting Equipment)

[0245] As shown in FIG. 39, in the preferred embodiment, a first centralseal-up housing 2A and a pair of left and right second seal-up housings2B are used. As shown in FIG. 38, the abovementioned first seal-uphousing 2A is provided with a first and second split housings 221 and222, which are obtained by being divided into two sections in thecircumferential direction, and a guide bushing 222 a. Furthermore, thesecond seal-up housings 2B (FIG. 39) are also divided into two sectionsin the circumferential direction. As shown in FIG. 40(a), rubber rings224 are used to seal up between the respective housings 221 (FIG. 39),222, 2A and 2B and between the second seal-up housings 2B and theexisting pipe 1.

[0246] The abovementioned second split housing 222 has a bifurcatedportion 222 b protruding in the diametrical direction C of the existingpipe 1, and the main bearing 232 is attached to the abovementionedbifurcated portion 222 b so as to freely advance and retreat in thediametrical direction C of the existing pipe 1 via the guide bushing 222a. Rubber rings 224 are used to seal up between the guide bushing 222 a,bifurcated portion 222 b and the main bearing 232. An opening 222 c intowhich a columnar cutting tool 230 is inserted is formed at theabovementioned bifurcated portion 222 b at the second split housing 222.

[0247] Cutting equipment 3 is attached to the guide bushing 222 a fixedat the abovementioned first seal-up housing 2A via the main bearing 232.That is, a first motor 231 (an example of a prime mover) for rotating acutting tool is fixed upward of the main bearing 232. On the other hand,the cutting tool 230 is disposed inside of the abovementioned mainbearing 232 (cutter attaching housing). A cutting tool 230 is formed tobe integral with the main shaft (cutter shaft) 233 rotatably supportedat the main bearing 232. The first motor 231 causes the cutting tool 230to rotate via a coupling 234 fixed at the output shaft 231 a of thefirst motor 231 and the main shaft 233.

[0248] As shown in FIG. 40(b), the abovementioned cutting tool 230 has aplurality of blades 230 f on the roughly columnar tip end surface 230 dand outer circumferential surface 230 e. Furthermore, the main shaft 233is formed on the cutting tool 230 to be integral therewith. As shown inFIG. 38, the axial line 233 a of the cutting tool 230 and main shaft 233is established in the diametrical direction C of the existing pipe 1.The cutting tool 230 carries out a cutting motion by rotating around theaxial line 233 a set in the diametrical direction C of the existing pipe1. Furthermore, in the preferred embodiment, a cutting tool 230 having agreater diameter than that of the cutting tool 230 in the thirdpreferred embodiment is used. Moreover, the tip end of the cutting tool230 is pointed to be conical.

[0249] A cutting feed frame 236 is fixed at the above-mentionedbifurcated portion 222 b in FIG. 40(a). The cutting feed frame 236 isprovided with long bolts 236 a fixed at the bifurcated portion 222 b anda top plate 236 b fixed at the upper ends of the long bolts 236 a. Amale lead screw 237 for cutting feed is screwed in a bushing 236 csecured at the abovementioned top plate 236 b of the cutting feed frame236.

[0250] By turning and screwing the male lead screw 237 for cutting feedin the cutting feed direction C, the main bearing 232 advances in thecutting feed direction C. Therefore, by feeding the cutting tool 230together with the main bearing 232 in the cutting feed direction C andcausing the cutting tool to be advanced into the opening 222 c, it ispossible to slit the existing pipe 1 by the cutting tool 230 as shown inFIG. 41. Furthermore, since the guide bushing 222 a is fixed at thecutting feed frame 236 via a connection metal fitting 238 in FIG. 38,the guide bushing 222 a can be withdrawn together with the cutting feedframe 236 after the slitting is completed.

[0251] In the preferred embodiment, a housing turning device 4 in FIG.39 is provided, which turns the first seal-up housing 2A around theexisting pipe 1. The housing turning device 4 has a pair of secondmotors 242 for turning the seal-up housing. The corresponding secondmotor 242 rotates the drive gear 244 for turning the seal-up housing viathe output shaft 247. The corresponding drive gear 244 rotates thedriven gears 245 for turning the seal-up housing, which are fixed at thefirst seal-up housing 2A. Therefore, by turning the first seal-uphousing 2A by approximately 180 degrees around the existing pipe 1 whilerotating the cutting tool 230 in a cutting feed state in FIG. 41, it ispossible to slit the existing pipe 1 and to form a slit groove 12C inFIG. 45.

[0252] As shown in FIG. 40, the second seal-up housing 2B constitutes aslip preventing member 5A. The corresponding second seal-up housing 2Bis divided into two sections in the circumferential direction (R) (FIG.38) of the existing pipe 1. A number of set screws 251 are provided inthe circumferential direction R (FIG.38) at two points spaced from eachother in the axial direction S of pipe 1. A rotation guiding portion 250which slides via a liner 252 is secured at the connection portionbetween the abovementioned first seal-up housing 2A and the secondseal-up housing 2B. The abovementioned pair of second seal-up housings2B are fixed at the existing pipe 1 by the abovementioned set screws251. The above-mentioned second seal-up housings 2B guide the firstseal-up housing 2A via the abovementioned rotation guiding portion 250and prevent the first seal-up housing 2A from slipping or shaking in theaxial direction S of the existing pipe 1. Therefore, the first seal-uphousing 2A is able to be smoothly turned when turning around theexisting pipe 1. Furthermore, a ball bearing may be used instead of aliner 252.

[0253] Slitting Process

[0254] Next, a description is given of a sequence of slitting.

[0255] First, in a state where fluid (water) is flowing in the existingpipe 1 in FIG. 39, the workmen attach the first and second seal-uphousings 2A and 2B to the existing pipe 1 and both split housings 221and 222 by assembling bolts in FIG. 38. Thus, as shown in FIG. 39, thefirst and second seal-up housings 2A and 2B enclose and seal up theexisting pipe 1 in an airtight state. Furthermore, the cutting equipment3 is attached, in advance, to the guide bushing 222 a of the firstseal-up housing 2A.

[0256] Next, as shown in FIG. 42(a) and FIG. 42(b), a position to beslit by acutting tool 230 is determined. That is, the housing turningdevice 4 in FIG. 39 is driven, wherein the first seal-up housing 2A andcutting equipment 3 are turned until the position wherein the axial line233 a (FIG.42) of the cutting tool 230 is made roughly horizontal.

[0257] Next, as the workmen drive the first motor 231 in FIG. 38, thecorresponding first motor 231 rotates the cutting tool 230 around theaxial line 233 a of the main shaft 233, wherein the cutting tool 230 iscaused to perform a slitting motion by which the existing pipe 1 is slitby rotations of the cutting tool 230. In a state where the cutting tool230 is performing a slitting motion, the workmen screw the male leadscrew 237 for cutting feed in the cutting feed direction C,concurrently, as shown by an alternate long and two dashes line in FIG.42(b), the cutting tool 230 advances to the position where the tip endsurface 230 d thereof passes through a part of the wall la of theexisting pipe 1. Thus, the cutting feed of the cutting tool 230 in thedirection C is completed.

[0258] After that, as the workmen drive the second motor 242 for turningthe housing in FIG. 39, the first seal-up housing 2A is turned, via apair of drive gears 244 and driven gears 245, around the existing pipe 1in a state where it is guided by the second seal-up housings 2B.Thereby, as shown in FIG. 42(c), the cutting tool 230 rotates on themain shaft 233 while turning along the outer circumference of theexisting pipe 1 by approximately 180 degrees (for example, 160 degrees)together with the first seal-up housing 2A, wherein the existing pipe issemi-annularly slit to form a slit groove 12C thereat. The correspondingslit groove 12C is cut open in a range of approximately 180 degrees inthe circumferential direction R of the existing pipe 1.

[0259] That is, the abovementioned second motor 242 (FIG.38) turns thecutting tool 230 in the circumferential direction R by causing the firstseal-up housing 2A to be turned in the circumferential direction R(FIG.38) of the existing pipe 1, as shown in FIG. 42(b) and FIG. 42(c),a cutting feed motion is given to the cutting tool 230. Thereby, thecutting tool 230 semi-annularly slits the above-mentioned existing pipe1 in order to form a slit groove 12C at the existing pipe 1. After thecorresponding slitting is completed, the cutting tool 230 is returned toits original position as shown by the arrow of an alternate long and twodashes line. Thereafter, the workmen remove the housing turning device 4in FIG. 39.

[0260] Furthermore, by attaching a water discharge valve at the mainbearing 232, cutting chips may be discharged through the water dischargevalve when slitting.

[0261] Cutting Equipment Removing Equipment

[0262] Next, the workmen remove the cutting equipment 3 by the methoddescribed below. That is, as shown in FIG. 43, the workmen connects anoperation sluice valve 273 to the bifurcated portion 222 b, andfurthermore an operation upper chamber 274 is connected to the operationsluice valve 273 so as to overlap thereon. When carrying out theconnection, the workmen connect a frame 236 for cutting feed to the tipend of a lifting shaft 276 passing through the operation upper chamber274. After the connection is finished, the workmen remove nuts 239.After the nuts 239 are removed, the workmen raise the lifting shaft 276in FIG. 44 and remove the cutting equipment 3 from the first seal-uphousing 2A into the operation upper chamber 274. After the cuttingequipment is removed, the workmen close the operation sluice valve 273.After the valve is closed, the workmen separate the operation upperchamber 274 from the operation sluice valve 273.

[0263] Next, a description is given of a structure of sluice valve bodyof a valve to be inserted in a line.

[0264] A valve is provided with a sluice valve body 8 a shown in FIG.45. The corresponding sluice valve body 8 a is provided with rubberpacking 8 d. The corresponding rubber packing 8 d closes the slit groove12C as the sluice valve body 8 a invades inside of the existing packing1 through the slit groove 12C, and is pressure-fitted to the innersurface 1 b of the existing pipe 1. That is, the rubber packing 8 dconsists of a first rubber packing portion 8 d 1 pressure-fitted to theslit surface 12 f of the slit groove 12C and a second rubber packingportion 8 d 2 pressure-fitted to the inner circumferential surface lb ofthe existing pipe 1 in a series as shown in FIG. 46(c) and FIG. 46(d).Furthermore, a first attaching groove 8 a 1 and a second attachinggroove 8 a 2 are formed at the abovementioned sluice valve body 8 a inorder to attach the first and second rubber packing portions 8 d 1 and 8d 2 which are shown in FIG. 46(a) and FIG. 46(b).

[0265] Valve Inserting Process

[0266] Next, the workmen accommodate the valve cover 8 b in FIG. 47 andthe abovementioned sluice valve body 8 a in the operation upper chamber274 and connect the corresponding operation upper chamber 274 to theoperation sluice valve 273. The sluice valve 8A is provided with aspindle 8 c for opening and closing the sluice valve body 8 a. Thecorresponding sluice valve 8A constitutes a valve so that the sluicevalve body 8 a in FIG. 45 invades the existing pipe 1 through the slitgroove 12C and the rubber packing 8 d secured at the sluice valve body 8a is pressure-fitted to the cutting surface 12 f of the existing pipe 1and the inner circumferential surface 1 b of the existing pipe 1. Thatis, the existing pipe 1 constitutes a part of the valve housing of thesluice valve 8A.

[0267] After the operation upper chamber 274 in FIG. 47 is attached inplace, the workmen opens the operation sluice valve 273 as shown in FIG.48 and shifts down the lifting shaft 276, wherein the valve cover 8 b isbrought into contact with the bifurcated portion 222 b. After the valvecover 8 b is brought into contact therewith, the workmen connect thevalve cover 8 b to the bifurcated portion 222 b by flange bolts 8 e.After the connection, the workmen withdraw the operation upper chamber274 and operation sluice valve 273. Thereafter, the workmen press rubberrings 264 into the packing insertion portions 260 of the second seal-uphousing 2B in FIG. 49 and attach split press rings 265 to the secondseal-up housing 2B. Thus, the sluice valve 8A is disposed at the pointcorresponding to the slit groove 12C, wherein the sluice valve 8A isinserted in a line 1A.

[0268] Herein, in the fourth preferred embodiment, since rubber packing8 d is pressure-fitted to the slitting surface 12 f and the innercircumferential surface 1 b of the existing pipe 1 in FIG. 45, that is,the existing pipe 1 is used as a valve housing, a great external forceis applied to the existing pipe 1. However, in this preferredembodiment, the width of a slit groove 12C formed at the existing pipe 1is made small, in particular no thin portion is produced at the existingpipe 1, and there is no fear that the existing pipe 1 is damaged whenthe line 1A is closed with a sluice valve body 8 a.

[0269] Furthermore, since, when the sluice valve body 8 a is closed, thesluice valve body 8 a is supported in the axial direction S of pipe 1 onthe slitting surface 12 f via the first rubber packing portion 8 a 1,the valve body 8 a is scarcely deformed even though it is given pressurewhen stopping water. Therefore, it is possible to make the spindle 8 cslender. Furthermore, since the width of the slitting groove 12C issmall, the force, with which the valve body 8 a is pressed upward byhydraulic pressure, is also small. Therefore, the spindle 8 c can bemade slender.

[0270] Furthermore, in the abovementioned second preferred embodimentthrough the fourth embodiment, although a seal-up housing is dividedinto the first seal-up housing 2A and second seal-up housing 2B and apart of the seal-up housing, that is, the first seal-up housing 2A isturned, in the present invention, the first seal-up housing 2A andsecond seal-up housing 2B may be formed to be integral with each other.In this housing, a slip preventing member is separately provided asideof the seal-up housing, wherein the entire seal-up housing is turned.This example is shown by the following modified version of theembodiments.

[0271] Modified Version

[0272]FIG. 50 through FIG. 61 show a modified version of the fourthpreferred embodiment.

[0273] Hereinafter, after a description is given of the seal-up housingof the present modified version, a description is given of a pipingstructure thereof.

[0274] Seal-Up Housing

[0275] As shown in FIG. 50(a), the seal-up housing 2 is divided into thefirst and second split housings 211 and 212, wherein the split surface215 is sealed up by rubber packing 214 shown in FIG. 50(b). Furthermore,the split surface 215 of the two split housings 211 and 212 isconstructed so that they are brought into contact with each other in ametal-to-metal touching state. Furthermore, a packing insertion portion260 into which rubber packing 264 in FIG. 52 is inserted is provided atboth ends of the seal-up housing 2.

[0276] As shown in FIG. 51(b), a bolt insertion opening 217 for fixing avalve cover and a bolt insertion opening 218 for fixing an operationsluice valve are formed at a flange 216 of the second split housing 212in FIG. 51(a). A hole 219 is to insert an assembling bolt thereinto.

[0277] Piping Structure

[0278]FIG. 52 through FIG. 55 show a piping structure.

[0279] In FIG. 52, a slit groove 12C is formed at the existing pipe 1.As shown in FIG. 53, the corresponding slit groove 12C is notched andcut open in a range of approximately 180 degrees in the circumferentialdirection of the existing pipe 1. The corresponding slit groove 12C isformed by slitting the existing pipe 1 by a cutting tool describedlater. As shown in FIG. 52, the corresponding groove 12C is formed sothat both ends 12 c 1 thereof in the circumferential direction is maderoughly U-shaped. Thus, since both ends 12 c 1 of the slit groove 12Cdraws a smooth curve, the sealing at the corresponding both ends 12 c 1is facilitated.

[0280] Furthermore, the portion excluding the above-mentioned both ends12 c 1 at the abovementioned slit groove 12C is formed to a fixed groovewidth W.

[0281] Furthermore, the slit surface 12 f forming the abovementionedslit groove 12C is set in a range from 45 through 90 degrees withrespect to the surface 1 c of the existing pipe 1 at the correspondingportion. That is, as shown in FIG. 53, the existing pipe 1 does not haveany thin portion at the peripheral edge portion 12Ce of the slit groove12C. Therefore, as shown in FIG. 54 and FIG. 55, even though rubberpacking 8 d of the valve body 8 a is pressure-fitted to the slitsurface-12 f, there is no fear that the existing pipe 1 is damaged. Forthis reason, it is possible to repeatedly open and close the sluicevalve 8A.

[0282] The abovementioned seal-up housing 2 is divided into two sectionsin the circumferential direction R of the existing pipe 1 and is sealedup by rubber packing 214, wherein the existing pipe 1 is enclosed andsealed up in an airtight state. The first split housing 211 is formedalong the outer circumferential surface of the existing pipe 1. On theother hand, the second split housing 212 has a hole 212 d which permitsthe sluice valve body 8 a to move in the diametrical direction C of theexisting pipe 1. The valve cover 8 b is fixed at the above-mentionedsecond split housing 212. The corresponding valve cover 8 b clogs thehole 212 d for moving the abovementioned second split housing 212. Theabovementioned valve body 8 b and the second split housing 212 form aspace in which the sluice valve body 8 a is accommodated when the valveis opened in FIG. 53.

[0283] As shown in FIG. 54, the abovementioned sluice valve body 8 a hasrubber packing 8 d. The corresponding rubber packing 8 d is formed sothat the first rubber packing 8 d 1 which is brought into contact withthe slit surface 12 f (shown with a broken line in FIG. 55) forming theslit groove 12C and the second rubber packing 8 d 2 which is broughtinto contact with the inner circumferential surface 1 b of the existingpipe 1 are made integral with each other. The corresponding rubberpacking 8 d is baked to the sluice valve body 8 a to be integraltherewith. As shown in FIG. 52 and FIG. 54, the above-mentioned sluicevalve body 8 a is moved in the diametrical direction C of the existingpipe 1 in the seal-up housing 2 if the spindle (valve rod) 8 c isturned. The above-mentioned sluice valve body 8 a invades the inside ofthe existing pipe 1 through the abovementioned slit groove 12C, whereinthe rubber packing 8 d is brought into contact with the slit surface 12f and the inner circumferential surface 1 b of the existing pipe 1, andfluid flowing in the existing pipe 1 is stopped. Furthermore, the innercircumferential surface 1 b of the existing pipe 1 in the presentpreferred embodiment is finished with mortar lining.

[0284] Cutting Equipment (Slitting Equipment)

[0285] In the slitting process, as shown in FIG. 56, the abovementionedseal-up housing 2 is provided with the first and second split housings211 and 212 split into two sections in the circumferential direction anda guide bushing 212 a.

[0286] The abovementioned second split housing 212 has a bifurcatedportion 212 b protruding in the diametrical direction C of the existingpipe 1, wherein a main bearing 232 to support the main shaft 233 isattached to the corresponding bifurcated portion 212 b slidably in thediametrical direction C of the existing pipe 1 via the abovementionedguide bushing 212 a. As shown in FIG. 58(a), rubber rings 224 are usedto seal up between the abovementioned guide bushing 212 a, bifurcatedportion 212 b and main bearing 232. An opening 212 c in which a columnarcutting tool 230 is inserted is formed at the abovementioned bifurcatedportion 212 b in the second split housing 212.

[0287] Cutting equipment 3 is attached to the guide bushing 212 a fixedat the abovementioned seal-up housing 2 via the main bearing (toolattaching housing) 232. That is, A motor (one example of a prime mover)231 for rotating the tool is fixed upward of the main bearing 232. Onthe other hand, the abovementioned cutting tool 230 is disposed insidethe abovementioned main bearing 232. The cutting tool 230 is formed tobe integral with and at the main shaft (cutter shaft) 233 which isrotatably supported at the main bearing 232. The abovementioned motor231 causes the cutting tool 230 to rotate via the output shaft 231 a ofthe corresponding motor 231 and a coupling 234 fixed at the main shaft233.

[0288] As shown in FIG. 58(b), the abovementioned cutting tool 230 has aplurality of blades 230 f on the roughly columnar tip end surface 230 dand outer circumferential surface 230 e. Furthermore, the abovementionedmain shaft 233 is formed integral with the cutting tool 230.

[0289] Furthermore, in the preferred embodiment, in order that theslitting surface 12 f is tapered as shown in FIG. 52, a tapered portion230 t is provided at the cutting tool 230 in FIG. 58(b). Furthermore, inorder to prevent the abovementioned tapered portion 230 t from enteringtoward the center of the existing pipe 1 excessively, the cutting tool230 is provided with a cutting feed stopper 230 s fixed thereon.

[0290] The cutting feed stopper 230 s is made of hard resin, and it isfavorable that the cutting feed stopper 230 s is provided with groovesthrough which cutting chips are permitted to escape. In the preferredembodiment, the cutting feed stopper may be secured at the guide bushing212 a instead of being secured at the cutting tool 230.

[0291] As shown in FIG. 56, the axial line 233 a of the abovementionedcutting tool 230 and main shaft 233 is set in the diametrical directionC of the existing pipe 1. The abovementioned cutting tool 230 carriesout a slitting motion by being rotated around the abovementioned axialline 233 a established in the diametrical direction C of theabovementioned existing pipe 1.

[0292] A cutting feed frame 236 is fixed at the above-mentionedbifurcated portion 212 b in FIG. 58(a). The corresponding cutting feedframe 236 is provided with long bolts 236 a fixed at the abovementionedbifurcated portion 212 b and a top plate 236 b fixed on the upper endsof the corresponding long bolts 236 a. A male lead screw 237 for cuttingfeed is screwed in a bushing 236 c secured at the abovementioned topplate 236 b of the above-mentioned cutting feed frame 236.

[0293] By turning and screwing the male lead screw 237 for cutting feedin the cutting feed direction C, the main bearing 232 advances in thecutting feed direction C. Therefore, by causing the cutting tool 230 toadvance in the opening 212 c by feeding the cutting tool 230 togetherwith the main bearing 232 while rotating the cutting tool 230, it ispossible to slit the existing pipe 1 by the cutting tool 230 as shown inFIG. 59. Furthermore, the abovementioned guide bushing 212 a is fixed atthe cutting feed frame 236 via a connection metal fitting 238 in FIG.56, and it is withdrawn together with the cutting feed frame 236 afterthe slitting is completed.

[0294] As shown in FIG. 57, a slip preventing member 5 is provided atboth sides of the abovementioned seal-up housing 2. The correspondingslip preventing member 5 is fixed at the existing pipe 1 by a number ofset screws 251 and is brought into contact with both sides of theseal-up housing 2 via a liner 252. Thereby, the slip preventing member 5guides the seal-up housing 2 and prevents the seal-up housing 2 fromslipping or shaking in the axial direction S of the existing pipe 1.Therefore, the seal-up housing 2 is smoothly turned when turning aroundthe existing pipe 1. Furthermore, a pressing screw 253 presses the liner252 to the seal-up housing 2.

[0295] Slitting Process

[0296] Next, a description is given of a sequence of slitting.

[0297] First, in a state where fluid (water) is flowing in the existingpipe 1 in FIG. 57, the workmen attach the seal-up housing 2 to theexisting pipe 1 and assemble both split housings 211 and 212 byassembling bolts (not illustrated). Thus, as shown in FIG. 57, theseal-up housing 2 encloses and seals up the existing pipe 1 in anairtight state. Furthermore, the cutting equipment 3 is attached, inadvance, to the guide bushing 212 a.

[0298] Next, as shown in FIG. 60(a) and FIG. 60(b), a slitting positionto be slit by the cutting tool 230 is determined. That is, the workmen,manually or by using a winch, turn the seal-up housing 2 and cuttingequipment 3 to the position where the axial line 233 a of the cuttingtool 230 is roughly horizontal. Furthermore, in the present embodiment,an operation handle and a speed reduction mechanism, which are used toturn the seal-up housing 2, may be provided.

[0299] Next, as the workmen drive the motor 231 in FIG. 56, thecorresponding motor 231 turns the cutting tool 230 around the axial line233 a of the main shaft 233 and causes the cutting tool 230 to perform aslitting motion, by which the existing pipe 1 is slit by thecorresponding cutting tool 230. In a state where the cutting tool 230 isperforming the corresponding slitting motion, the workmen screw the malelead screw 237 for cutting feed in the cutting feed direction C,concurrently, as shown with an alternate long and two dashes line inFIG. 60(b), the tip end surface 230 d of the cutting tool 230 advancesto the position where the tip end surface passes through a part of thewall la of the existing pipe 1. At this time, the cutting feed stopper230 in FIG. 59 is brought into contact with the outer circumferentialsurface of the existing pipe 1. Thus, the cutting feed by the cuttingtool 230 is completed.

[0300] After the cutting feed is completed, the workmen turn the seal-uphousing 2 around the existing pipe 1 as shown in FIG. 60(b) and FIG.60(c), thereby, the cutting tool 230 is turned around the axial line 233a while turning by approximately 180 degrees (for example, 160 degrees)along the outer circumference of the existing pipe 1 together with theseal-up housing 2, wherein the existing pipe 1 is semi-annularly slit,and a slit groove 12C is formed at the existing pipe 1.

[0301] After the slitting is completed, the cutting tool 230 in FIG.60(c) is returned to the original position as shown with the arrow of analternate long and two dashes line. Furthermore, in order that the waterstopping made by the sluice valve 8A (FIG.53) inserted in a line lateris made sufficient, it is necessary that the cutting tool 230 isreturned to the central position of the cutting groove 12C.

[0302] Cutting Equipment Removing Process

[0303] Next, the workmen removes the cutting equipment 3 in FIG. 61 by amethod similar to that in the above-mentioned embodiment, and further,as shown in FIG. 52 and FIG. 53, the sluice valve 8A is inserted into aplace corresponding to the slit groove 12C in a line 1A.

[0304] Thus, in the present piping structure, since the width of theslit groove 12C in FIG. 52 is small, it is possible to decrease the sizeof the seal-up housing 2.

[0305] A cutting tool for slitting the slit groove 12C according to theinvention may be a conical trapezoidal type as shown in FIG. 62(a), aconical type as shown in FIG. 62(b), or a columnar type as shown in FIG.62(c). Furthermore, as blades 230 f, a number of diamond grains may beemployed, as shown in FIG. 62(b) and FIG. 62(c), in addition to ultrahard chips.

[0306] Furthermore, in the present piping structure, as a method forslitting the existing pipe 1, it is not necessary to turn the seal-uphousing 2, but as shown in FIG. 62(d), a roughly columnar cutting tool230 is parallelly moved in the circumferential direction R in order toform a slit groove 12C. Furthermore, as another method, as shown in FIG.62(e), the slit groove 12C may be also formed by machining the existingpipe 1 so as to press the side of a cutting tool 230 consisting of acolumn-shaped miller to the existing pipe 1.

[0307] Fifth Preferred Embodiment

[0308]FIG. 63 through FIG. 68 show the fifth preferred embodiment.Hereinafter, a description is given of an existing pipe cut-off methodand a method for inserting a valve in a line without stopping passage ofwater according to the fifth preferred embodiment.

[0309] First, the workmen attach the seal-up housing 2 to the existingpipe 1 as shown in FIG. 63(a) through FIG. 63(d) and enclose and seal upa part of the outer circumference of the existing pipe 1 by the seal-uphousing 2 in an airtight state.

[0310] Since the abovementioned seal-up housing 2 constitutes a part ofa valve housing of a sluice valve which is inserted by the presentmethod, it is divided into the first split housing 321, the second splithousing 322 and lower cover 323. The abovementioned first split housing321 and the second split housing 322 are fixed by a slip preventingmember 5B having set screws 351 shown in FIG. 64 via a liner 352 so thatthey do not slip in the axial direction S of pipe 1. The abovementionedlower cover 323 is such that a cover body 345 to clog an opening of thebifurcated portion 326 of the second split housing 322, cylindricalportion 346 and flange portion 347 are made integral with each other.The tip end of the stopper bolt 327 secured at the flange 349 of thebifurcated portion 326 is brought into contact with the abovementionedcover body 345.

[0311] Furthermore, rubber packing 324 is used to seal up the slittingportion.

[0312] Cutting equipment 3 is attached to the lower cover 323 of theabovementioned seal-up housing 2. The corresponding cutting equipment 3has a cutting tool 330. As the cutting tool 330, for example, it isfavorable to use an end mill as in the second preferred embodiment. Thecutting tool 330 is housed in the seal-up housing 2. The cutting tool330 is fixed at the tip end of the main shaft (cutter shaft) 331 and isrotatably supported at the main bearing 332 via the main shaft 331.

[0313] The main bearing 332 is slidable in the cylindrical portion 346of the abovementioned lower cover 323, wherein, by turning the mainshaft feed screw 333, the main bearing 332 moves vertically in the axialdirection in the lower cover 323. That is, the cutting tool 330protrudes toward the wall la of the existing tube 1 in the seal-uphousing 2, and is advanced and retreated in the diametrical direction Cof the existing pipe 1. A coupling portion 334 is provided at the upperportion of the abovementioned main bearing 332. The correspondingcoupling portion 334 connects the output shaft 336 of a prime mover 335such as a motor to the main shaft 331.

[0314] After the abovementioned seal-up housing 2 is attached in place,the workmen connect a water discharge valve 328 to the water dischargeport 348 secured at the lower cover 323 in FIG. 63(c). Furthermore, theworkmen fix a pressing cover 329, by which the cover body portion 345 ofthe lower cover 323 in FIG. 64 is pressed from upwards, at the flange349 of the bifurcated portion 326 with bolts 350.

[0315] Next, the workmen drive the prime mover 335 in FIG. 64, thecutting tool 330 rotates around the axial line 331 a of the main shaft331. In this state, if, by turning the main shaft feed screw 333, theworkmen feed the cutting tool 330 to the position where the cutting tool330 passes through the wall 1 a of the existing pipe 1 in thediametrical direction C thereof, a circular hole is drilled at theexisting pipe 1. After the drilling is completed, the workmen turn theseal-up housing 2 in FIG. 63(c) in the circumferential direction R ofthe existing pipe 1 at a low speed to turn (feed) the cutting tool 330in the same circumferential direction R, wherein a part (illustrated byan alternate long and two dashes line in FIG. 63(d)) of the existingpipe 1 is slit by the cutting tool 330. Herein, since, in the presentcut-off method, the cutting is performed by using an end mill, noannular cut-off section is produced. The annularly slit and cut-openportion 12 becomes a space in which a sluice valve body 8 a in FIG. 66described later perpendicularly moves.

[0316] As the method for turning the abovementioned seal-up housing 2, awinch or other large-sized construction machines may be employed. If theexisting pipe is made of vinyl chloride, the seal-up housing 2 may bemanually turned. Cutting chips produced by the above-mentioned cuttingor slitting are discharged through a water discharge valve 328(FIG.63(c)) opened during the slitting.

[0317] Next, the workmen remove the prime mover 335 in FIG. 64 and presscover 329, and remove the cutting equipment 3 by an already known methoddescribed later. That is, as shown in FIG. 65, the workmen connect anoperation sluice valve 373 to the flange 349 of the bifurcated portion326, and furthermore connect an operation upper chamber 374 to theoperation sluice valve 373 so as to overlap each other. When connectingthem, the flange 360 is connected to the lower end portion of thelifting shaft 376 passing through the operation upper chamber 374. Afterthe connection is completed, the workmen remove stopper bolts 327 inFIG. 64. Thereafter, they raise the lifting shaft 376 in FIG. 65 andremove the cutting equipment 3 and the lower cover 323 from the seal-uphousing 2 into the operation upper chamber 374. Thereafter, the sluicevalve 373 is closed. After the sluice valve is closed, the workmenseparate the operation upper chamber 374 from the operation sluice valve373.

[0318] Next, the workmen connect the abovementioned operation upperchamber 374, in which the valve cover 8 b and sluice valve body 8 a inFIG. 66(a) and FIG. 66(b) are housed, to the flange 375 of the operationsluice valve 373. The sluice valve 8A inserted in a line 1A is providedwith a spindle 8 c for opening and closing the sluice valve body 8 a.The corresponding sluice valve 8A constitutes such a valve that byturning the spindle 8 c, the sluice valve body 8 a invades the slit andcut-open portion 12 and rubber packing 8 d for sealing, which is securedat the sluice valve body 8 a, and is pressure-fitted to the innercircumferential surface 321 a of the seal-up housing 2 in FIG. 68.

[0319] After attaching the abovementioned operation upper chamber 374 inFIG. 66(a), the workmen open the operation sluice valve 373 as shown inFIG. 66(b), slightly shift down the lifting shaft 376, and as shown inFIG. 67, coincide the flange 8 f of the valve cover 8 b with the flange349 of the bifurcated portion 326. Thereafter, the workmen insert aflange bolt 8 e through the flange 349 to fix the valve cover 8 b at thesecond split housing 322. After that, the workmen remove the fixingbolts 361, by which the operation sluice valve 373 is fixed, afterwithdrawing the operation upper chamber 374, and withdraws the operationsluice valve 373. Thus, as shown in FIG. 68, the sluice valve 8A isinstalled at a place corresponding to the slit and cut-open portion 12,wherein the sluice valve 8A is inserted in a line 1A.

[0320] In the abovementioned method, since a cutting tool 330 in FIG.63(c) is attached to the seal-up housing 2, it is possible to draw theinner circumference of the seal-up housing 2 to the outer circumferenceof the existing pipe 1. Therefore, the seal-up housing 2 can be madesmall-sized.

[0321] Modified Version

[0322]FIG. 69 and FIG. 70 show a modified version of the fifth preferredembodiment.

[0323] In FIG. 69, in the present modified version, the entire seal-uphousing 2C constitutes the valve housings 321, 322 and the valve cover322A. In the corresponding seal-up housing 2C, a sluice valve body 8 awhich moves in the diametrical direction C of the existing pipe 1 ishoused. On the other hand, the corresponding seal-up housing 2C isprovided with a cylindrical portion 380 for take-out, which has anoperation sluice valve 373A, at the opposite side of the sluice valvebody 8 a. In the modified version, after the end mill 330 is cut in fromthe state shown in FIG. 69, the existing pipe 1 is cut off as in theabovementioned fourth preferred embodiment if the workmen turn thecutting equipment 3 together with the seal-up housing 2C. After thecutting is completed, the workmen close the operation sluice valve 373Awhile removing the cutting equipment 3, and remove the cutting tool 330,etc.

[0324] Thereafter, the workmen close the opening of the cylindricalportion 380 for take-out with a clogging member 381 which clogs thecylindrical portion 380 in FIG. 70. That is, after the workmen connect aclogging cap 382 to the flange portion 383 of the cylindrical portion380 for take-out, they open the operation sluice valve 373A and screwthe male screw member 384, wherein the opening of the cylindricalportion 380 is shaped so as to match the inner circumferential surfaceof the seal-up housing 2C and is closed by the clogging member 381.Furthermore, the abovementioned clogging member 381 is made of a rubbercap having curvature along the inner circumferential surface 321 a ofthe abovementioned seal-up housing 2. The corresponding clogging member381 is fixed at and attached to the tip end of an operation rod 385slidable at the clogging member 382 via a male screw member 384.

[0325] Furthermore, the other construction and method of the modifiedversion are the same as those of the abovementioned fifth preferredembodiment, and they are given the same reference numbers as those ofthe fifth embodiment, wherein the description thereof is omitted.

[0326]FIG. 71 shows another modified version of the fifth preferredembodiment.

[0327] In the apparatus according to the modified version in FIG. 69,the modified version in FIG. 71 may be used in a housing where a largespace can not be secured around the surrounding of the existing pipe 1.In this modified version, the seal-up housing 2C consists of the firstsplit housing 321, second split 322, first lower cover 323A, and secondlower cover 325A. The cutting equipment 3 is attached to the cylindricalportion 380 for take-out, but is not attached to the first lower cover323A. The sluice valve body (not illustrated) is attached by the samemethod as in the abovementioned fourth preferred embodiment.Furthermore, as in this preferred embodiment, if power is transmitted bya bevel gear 390, the downsizing of equipment can be secured.

[0328] Sixth Preferred Embodiment

[0329]FIG. 78 through FIG. 85 show a sixth preferred embodiment.

[0330] The sixth preferred embodiment is preferably employed for a pipeof small diameter, for example, 3 inches through 12 inches. The seal-uphousing and the piping structure after an appointed valve is insertedare approximate to the modified versions illustrated in FIG. 50 throughFIG. 61. Herein, parts which are different from the modified versionsare mainly described below.

[0331] Seal-Up Housing

[0332] In this preferred embodiment, as shown in FIG. 78 and FIG. 79, asluice valve body 8 a and a spindle 8 c are accommodated in advance inthe seal-up housing 2. A valve cover 8 b also constitutes the seal-uphousing 2 together with the first split housing 211 and the second splithousing 212.

[0333] As shown in FIG. 79, a bifurcated portion 212 b, through which acutting tool 230 (FIG.80) passes, protrudes and is provided in thesecond split housing 212. The main bearing 232 is fixed at theabovementioned bifurcated portion 212 b in FIG. 80. The main bearing 232supports the main shaft 233 of the cutting tool 230 when performing acutting operation. On the other hand, a discharge opening 248 whichdischarges cutting chips produced during a cutting operation togetherwith water is provided at the abovementioned bifurcated portion 212 b.Furthermore, a discharge valve may be connected to the discharge opening248 as necessary.

[0334] Cutting Equipment

[0335] A ball valve (operation valve) 277 is connected to theabovementioned main bearing 232 and cutting equipment 3 is attached tothe corresponding ball valve 277. The cutting equipment 3 is used toform a semi-annular slit groove 12C (FIG.78) as in the abovementionedfourth preferred embodiment, wherein the cutting tool 230 is rotated bya rotating force of a prime mover such as a motor and an engine alongwith feeding the cutting tool 230 in the diametrical direction C, and acutting motion is performed. The structure of the cutting equipment 3 issimilar to that of a hole saw type drilling machine used withoutstopping passage of water, which has been already known. Therefore,detailed illustration and description thereof are omitted herein.

[0336] As shown with an imaginary line in FIG. 78, a sluice valve body 8a is disposed in advance at a place corresponding to the slit groove 12Cslit by the abovementioned cutting tool 230.

[0337] Slitting Process

[0338] Next, a description is given of the sequence of slitting.

[0339] First, the workmen attach a seal-up housing 2 to an existing pipe1 in a state where water flows in the existing pipe 1 in FIG. 79, andconcurrently, assemble both split housings 211 and 212 by assemblingbolts (not illustrated). After that, the cutting equipment 3 in FIG. 80is attached in advance to the second split housing 212 of the seal-uphousing 2 via a ball valve 277. Thus, as shown in FIG. 78, the seal-uphousing 2 encloses and seals up the existing pipe 1 in an airtightstate.

[0340] Next, the seal-up housing 2 is turned, and as shown in FIG. 81, aslitting position carried out by the cutting tool 230 is established.That is, manually or by using a winch, the workmen turn the seal-uphousing 2 and cutting equipment 3 to the position where the axial line233 a of the cutting tool 230 is made roughly horizontal.

[0341] Furthermore, as the workmen drive the prime mover of the cuttingequipment 3, the corresponding prime mover causes the cutting tool 230to rotate around the axial line 233 a of the main shaft 233 and causes aslitting motion to be carried out, by which the existing pipe 1 is slitby rotations of the corresponding cutting tool 230. If the cutting tool230 is fed in the cutting feed direction C in a state where the cuttingtool 230 is performing the corresponding slitting motion, as shown withalternate short and long two-dashed lines, the cutting tool 230 shortlyadvances to the position where the tip end surface 230 d thereof, andpenetrates a part of the pipe wall la of the existing pipe 1. Thus, thecutting feed of the cutting tool 230 in the direction C is completed.

[0342] After that feed is completed, the workmen turns the seal-uphousing 2 around the existing pipe 1 in the circumferential direction Rof the existing pipe 1 in FIG. 81. Thereby, the cutting tool 230 isturned around the axial line 233 a while turning approximately 150 to160 degrees along the outer circumference of the existing pipe 1together with the seal up housing 2, wherein the cutting tool 230semi-annularly slits the existing pipe 1 as in FIG. 82, wherein a slitgroove 12C is formed in the existing pipe 1.

[0343] Cutting Equipment Removing Process

[0344] After the abovementioned slit groove 12C is formed, the dischargeopening 248 is clogged by a plug (not illustrated). After that, thecutting tool 230 is retreated, and the ball valve 277 is closed. Afterthe ball valve is closed, the cutting equipment 3 is removed from theseal-up housing 2. After it is removed, the seal-up housing 2 is turnedback from the position shown in FIG. 82 to its original position asshown in FIG. 83. Thereafter, a rubber ring 264 and a split press ring265, which are shown in FIG. 84, are attached. Here, insertion(installation) of the valve in a line is completed.

[0345] The sluice valve body 8 a is closed as shown in FIG. 84 and FIG.85 where optional. Thus, in this preferred embodiment, no operationupper chamber is required, and the operation valve 277 can be maderemarkably small. Furthermore, since it is not necessary that, after theslitting is completed, the operation valve 277 is opened and the sluicevalve body 8 a is accommodated in the seal-up housing 2, the timerequired for the operation can be remarkably shortened.

[0346] As described above, although some preferred embodiments of theinvention are explained with reference to the accompanying drawings,they does not intend to limit the scope of the invention, that is, oneskilled in the art is able to easily make various types of variationsand modifications in a clear range with reference to the specificationhereof.

[0347] For example, an engine may be employed in addition to a motor asa prime mover which gives a slitting motion to a cutting tool.Furthermore, a prime mover is installed on the ground, and power of thecorresponding prime mover is transmitted to a cutting tool via itscutter shaft by a flexible shaft. Furthermore, after an existing pipe isenclosed and sealed up by a seal-up housing, a cutting tool may beattached to the corresponding seal-up housing. Still furthermore, afterthe existing pipe 1 is cut off or slit, a branch pipe may be connectedto the seal-up housing via a sluice valve.

[0348] Furthermore, when cutting or slitting the existing pipe 1 by acutting tool, although it is generally favorable that the cutting toolis fed toward roughly the center in the diametrical direction of theexisting pipe as in the respective preferred embodiments, in the presentinvention, it is not necessary that the cutting tool is moved toward thecenter thereof. It is satisfactory that the cutting tool is fed in thediametrical direction.

[0349] Furthermore, the seal-up housing may be divided into three orfour sections in the circumferential direction. Still furthermore, avalve body may be inserted from any direction such as upward, sideway ordownward.

[0350] In addition, the present invention is applicable to not only awater pipe but also a gas pipe. That is, fluid flowing in an existingpipe may be gas or oil in addition to water. These are included in theinvention.

[0351] Therefore, it is easily understood that such variations andmodifications are included in the scope of the invention, which aredefined by the claims thereof.

What is claimed is: 1 An existing pipe cut-off method, comprising thesteps of: accommodating a cutting tool, which is fixed at a rotatablysupported cutter shaft and is provided with a plurality of blades, in aseal-up housing in a state where the cutting tool is attached to saidseal-up housing while enclosing, in an airtight state, a part of anexisting pipe by said seal-up housing which is divided into pluralsections in the circumferential direction of the existing pipe; andfeeding said cutting tool roughly in the cross direction of saidexisting pipe in a state of performing a slitting motion to slit saidexisting pipe by rotations of said cutting tool by causing said cuttingtool to rotate on said cutter shaft by power of a prime mover, whereinsaid cutting tool is caused to perform a feed motion with said cuttingtool turned in said circumferential direction by causing at least a partof said seal-up housing to turn in said circumferential direction ofsaid existing pipe, and said existing pipe is cut off by said cuttingtool. 2 An existing pipe cut-off method as set forth in claim 1, furthercomprising the steps of: accommodating said cutting tool in each set ofsaid seal-up housings with two sets of said seal-up housings used whichare divided into plural sections in the circumferential direction ofsaid existing pipe, wherein each set of the seal-up housings is placedat two separate points spaced from each other in the axial direction ofsaid existing pipe, and a part of said existing pipe is enclosed in anairtight state by the respective seal-up housings; and slitting saidexisting pipe at two points by providing said cutting motion and feedmotion to the respective cutting tools, wherein a cut-off section to beremoved is formed. 3 An existing pipe cut-off method as set forth inclaim 2, wherein a spacer is provided between said two sets of seal-uphousings in order to determine the relative position of said two sets ofseal-up housings. 4 An existing pipe cut-off method as set forth inclaim 2, wherein after said cut-off is completed, said both seal-uphousings are further enclosed together with said existing pipe in anairtight state by an operation chamber, and after said both seal-uphousings are caused to slide onto said cut-off section, said cut-offsection is eliminated together with said both seal-up housings. 5 Avalve insertion method for inserting a valve in a line without stoppingpassage of water, wherein after said cut-off section in claim 4 iseliminated, a valve to seal a line is inserted into the line instead ofsaid cut-off section. 6 An existing pipe cut-off method as set forth inclaim 1, wherein said cutting tool is a disk-shaped cutting tool havinga number of said blades on the outer circumferential portion thereofprovided on a disk-shaped base. 7 An existing pipe cut-off method as setforth in claim 6, wherein said cutter shaft is set in parallel to theaxial direction of said existing pipe, and said disk-shaped cutting toolcarries out said slitting motion by rotation on said cutter shaft. 8 Anexisting pipe cut-off method as set forth in claim 7, wherein saiddisk-shaped cutting tool has non-directivity, which is able to slit saidexisting pipe even though said cutting tool rotates in any one of thetwo rotating directions on said cutter shaft. 9 An existing pipe cut-offmethod as set forth in claim 7, wherein said blades are made of diamondgrains, and said cutting tool is a diamond wheel. 10 An existing pipecut-off method as set forth in claim 9, wherein said cutter shaft isprovided with two diamond wheels in a state where they are spaced fromeach other in said axial direction of the pipe. 11 A valve insertionmethod for inserting a valve in a line without stopping passage ofwater, wherein after a cut-off section cut off by said two diamondwheels in claim 10 is removed from said seal-up housing together withsaid two diamond wheels, a valve to stop the passage of water isinserted into said line at the position corresponding to said cut-offsection instead of said cut-off section. 12 An existing pipe cut-offmethod as set forth in claim 1, wherein after said cutting tool is fedtoward roughly the center of said existing pipe in its diametricaldirection till a position where said cutting tool passes through a partof the wall of said existing pipe, said feeding motion is performedwhile causing said cutting tool to perform said slitting motion in astate where said cutting tool passes through said pipe wall. 13 Anexisting pipe cut-off method as set forth in claim 1, wherein a toolattaching housing which rotatably supports said cutter shaft isprovided; a bifurcated portion projecting roughly in the cross directionof said existing pipe is formed on one of a plurality of dividedhousings obtained by dividing said seal-up housing in saidcircumferential direction; said tool attaching housing is attached so asto be able to advance and retreat roughly in the cross direction of saidexisting pipe with respect to said bifurcated portion; and said seal-uphousing is thereby formed. 14 An existing pipe cut-off method as setforth in claim 1, wherein said cutting tool has a plurality of saidblades on the tip end face and outer circumferential surface of thecolumnar portion thereof. 15 An existing pipe cut-off method as setforth in claim 14, wherein the axial line of said cutter shaft isestablished roughly in the cross direction of said existing pipe, andsaid cutting tool turns around said axial line established roughly inthe cross direction of said existing pipe to carry out said slittingmotion. 16 A valve insertion method for inserting a valve in a linewithout stopping passage of water, wherein after said existing pipe iscut through by a cutting tool in claim 15 so that no cut-off sectionremains, the valve is inserted into a portion corresponding to thecut-open portion in a line. 17 A valve insertion method for inserting avalve in a line without stopping passage of water as set forth in claim16, wherein said seal-up housing constitutes at least a part of thehousing of the valve to be inserted thereinto. 18 A piping structurecomprising: an existing pipe having a slit groove notched and cut openso as to cover a range of approximately 180 degrees in thecircumferential direction of an existing pipe; a seal-up housing whichis divided into plural sections in the circumferential direction of saidexisting pipe and seals up said existing pipe in an airtight state; asluice valve body which has rubber packing being in contact with boththe inner circumferential surface of said existing pipe and a slitsurface forming said slit groove at said existing pipe in a closedstate, moves roughly in the cross direction of said existing pipe insaid seal-up housing, invades from said slit groove into said existingpipe, and stops the passage of fluid in said existing pipe by saidrubber packing being pressure-fitted to said inner circumferentialsurface and slit surface; and a valve rod by which said valve body iscaused to move roughly in the cross direction. 19 A piping structure asset forth in claim 18, wherein said slit groove is slit by a cuttingtool. 20 A piping structure as set forth in claim 19, wherein the slitsurface forming said slit groove is established so that an angle formedwith respect to the surface of said existing pipe at the correspondingportion is set in a range from 45 degrees to 90 degrees. 21 A pipingstructure as set forth in claim 20, wherein said slit groove is formedso that both end portions thereof are roughly U-shaped in thecircumferential direction. 22 A piping structure as set forth in claim21, wherein said slit groove is formed so that the portion excludingboth end portions thereof has a fixed groove width. 23 A pipingstructure as set forth in claim 18, wherein said seal-up housingcomprises: a first divided housing formed along the outer circumferenceof said existing pipe; a second divided housing having a hole in whichsaid sluice valve body moves, and accommodating at least a part of saidsluice valve body in an open state; and a valve cover for clogging saidhole of said second divided housing. 24 An existing pipe slittingmethod, comprising the steps of: accommodating a cutting tool, which isrotatably supported on the axial line established roughly in the crossdirection of an existing pipe and is provided with a plurality of bladeson the tip end face and outer circumferential surface of the columnarportion thereof, in a seal-up housing in a state where the cutting toolis attached to said seal-up housing while enclosing, in an airtightstate, a part of said existing pipe by said seal-up housing which isdivided into plural sections in the circumferential direction of theexisting pipe; and feeding said cutting tool roughly in the crossdirection of said existing pipe in a state of performing a slittingmotion to slit said existing pipe by rotations of said cutting tool bycausing said cutting tool to rotate on said axial line by power of aprime mover, wherein a slit groove cut open in a range of approximately180 degrees in the circumferential direction of said existing pipe isformed by slitting said existing pipe by said cutting tool in a range ofapproximately 180 degrees in the circumferential direction thereof bycausing said cutting tool to perform a feed motion with said cuttingtool turned in said circumferential direction by causing at least a partof said seal-up housing to turn in said circumferential direction ofsaid existing pipe. 25 An existing pipe slitting method as set forth inclaim 24, wherein after said cutting tool is fed toward roughly thecenter of said existing pipe roughly in the cross direction till aposition where said cutting tool passes through a part of the wall ofsaid existing pipe, said feeding motion is carried out while causingsaid cutting tool to perform said slitting motion in a state where saidcutting tool passes through said pipe wall. 26 An existing pipe slittingmethod as set forth in claim 24, wherein a tool attaching housing whichrotatably supports said cutting tool is provided; a bifurcated portionprojecting roughly in the cross direction of said existing pipe isformed on one of a plurality of divided housings obtained by dividingsaid seal-up housing in said circumferential direction; said toolattaching housing is attached so as to be able to advance and retreatroughly in the cross direction of said existing pipe with respect tosaid bifurcated portion; and said seal-up housing is thereby formed. 27A valve insertion method for inserting a valve in a line withoutstopping passage of fluid, wherein after said existing pipe is slitthrough in a range of approximately 180 degrees by a cutting tool inclaim 24, a valve having a valve body for stopping said existing pipe,which invades from said slit groove into said existing pipe, clogs saidslit groove and is pressure-fitted to the inner circumferential surfaceof said existing pipe, is inserted into a line. 28 A valve insertionmethod for inserting a valve in a line without stopping passage ofwater, wherein after said existing pipe is slit through in a range ofapproximately 180 degrees by a cutting tool of claim 24, a valve havinga valve body for stopping said existing pipe, which invades from saidslit groove into said existing pipe, clogs said slit groove and ispressure-fitted to the inner circumferential surface of said existingpipe, is inserted into a line. 29 A valve insertion method for insertinga valve in a line without stopping passage of fluid, as set forth inclaim 24, comprising the steps of: accommodating a sluice valve body inadvance in said seal-up housing in addition to said cutting tool beforeslitting said existing pipe in said range of approximately 180 degreesby said cutting tool, wherein said sluice valve body invades saidexisting pipe through said slit groove and maintains a closed state ofthe existing pipe by clogging said slit groove and concurrently, byclogging said existing pipe by being pressure-fitted to the innercircumferential surface of said existing pipe; and providing anoperation valve in said seal-up housing, which enables removal of saidcutting tool; wherein a sluice valve is inserted in a line by removingsaid cutting tool from said seal-up housing after slitting said existingpipe in the range of approximately 180 degrees by said cutting tool.